What is the real story around heat pumps? - Page 1
Forum section: electronics / general

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 17, 2024, 07:42:48 am
content: At the moment we are looking for a heat pump system to replace our wood burner. Asked three companies to come and give a quotation. The responses vary quite a bit.The first one suggested that heat pumps and specifically air to water systems are no good for where we live. They would consume more energy due to colder winters up here. (~500m above sea level) His advice was to look into fuel or pellet burners. Would be cheaper to install and on par with what we now pay per year for fire wood.Well guess again, his quotations for a fuel based system came out to be on par with a geothermal heat pump system, and the pellet based system even much higher, so no to those. Would also not solve my wife's problem with the smells.The second one suggested more or less the same for air to water heat pumps, due to the usage of additional direct electrical heating on very cold days. Annual energy consumption would be more then twice of what a geothermal system would use.The third one told us the opposite. Big fan of Mitsubishi Electric air to water heat pump. They would dimension it such that no additional direct electrical heating would be needed. They were also dismissive about the brand of heat pump offered by the second party. (De Dietrich) Did not receive their quotation yet, since they only came by yesterday.The problem I found with comparing all the data is the way the coefficient of performance is specified. There are tables that show the relations between outside temperature and requested inside water temperature, but to make a more or less correct calculation on energy consumption is not easy to do. I do know how much energy our house uses based on the data collection from my computer controlled heating system.The COP in the general data sheets is given mainly for 35 degree Celsius output water, and an input temperature that varies for the different systems. +7 and -7 for air to water systems and 0 for geothermal systems. (Based on glycol in the water)Sure they give the seasonal COP, but again at 35 degree Celsius. On colder days how ever our house needs the water to be between 45 and 55 degree Celsius, which is possible, but at what expense.So not an easy decision also given the fact that it is about a lot of money. (Between 15 - 40K euro)Any thoughts on what to believe and how to make a better decision between an air to water and a geothermal system?

author: RoGeorge
author_rank: Super Contributor
timestamp: February 17, 2024, 08:20:07 am
content: Heat pumps are advantageous when there is enough temperature difference, otherwise they'll become less efficient, or might not work at all. If a company selling heat pumps advice against buying a heat pump, better listen to them. Won't work.Anyway, if you decide to replace the current wood burner, do not remove it, and keep a way to switch back to burning wood if necessary. Heat pumps do not work without electricity, and electricity can not be stored, while a pile of wood is trivial to store indefinitely.

author: ebastler
author_rank: Super Contributor
timestamp: February 17, 2024, 08:30:06 am
content: Here's an online calculator with data for many real-world heatpump units, which lets you select the water output temperature and plots efficiency as a function of building heat loss. It assumes British weather though, which -- depending on where you are -- may distort the calculations somewhat. (Since you mentioned 500m altitude, I assume that's not in the Netherlands?)https://tools.bregroup.com/heatpumpefficiency/index.jsp

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 17, 2024, 08:46:18 am
content: Quote from: RoGeorge on February 17, 2024, 08:20:07 amThanks for the input, but my central heating system as is also needs electricity to workThe task of feeding the wood burner is daunting for me with my Fibromyalgia, and my wife hates the smell it gives. She loves to work outside in the garden and that becomes difficult on the days I have to burn the wood. In the colder periods it needs to burn every other day.It is not that a heat pump would not work, it is a question about who is telling the "truth". Geothermal will work for sure, but is more expensive due to in our case the need for vertical loops. Drilling is expensive.With geothermal the source is far more stable in temperature then when using air to water. But the COP goes down when you need 45 or 55 degrees Celsius of heating water to fulfill the need of the house. So both systems are less efficient when it is cold outside. Hence the seasonal COP being lower then the COP in ideal circumstances.The question is how big the difference is in annual energy consumption between the two systems. Air to water and geothermal. I know it depends on a lot of factors, like the local climate, the size of the house, the insulation of the house, etc.Another issue is the noise. We are very sensitive for it, and with the large fans in the external units the make more noise. There are a couple of installations in the village and when we walk by it bothers us. Not sure how it would be inside the house. The geothermal units are well insulated and produce not a lot of noise.It is hard to make a well informed decision.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 17, 2024, 08:47:30 am
content: Quote from: ebastler on February 17, 2024, 08:30:06 amThanks.Indeed we live in the middle of France.Edit: We are Dutch though, that is why I use the Dutch flag. Not out of chauvinism, just to show that Dutch is my native language.

author: Bicurico
author_rank: Super Contributor
timestamp: February 17, 2024, 09:23:12 am
content: Please check this channel, specifically the videos about heating and heat pumps.It is in German but I think you would understand what they are saying.https://m.youtube.com/@ProfRieckAfter watching many videos on the subject, mainly for the political aspect of it, I would say that heat pumps are a scam in most cases. There might be some use cases, where they make sense, but in most they don't.

author: Zarhi
author_rank: Contributor
timestamp: February 17, 2024, 10:40:22 am
content: Short answer:Upgrade Your utility power to 16 kW or more. Install electric boiler for 1500 euro and keep rest of the money to pay electric bills for next 7+ years.Keep Your wood burner in event of electricity fail and install backup UPS for circulation pump.Think for additional external insulation of house if possible. Upgrade windows with 4 Season Low-e 3 layer glasses.Long answer:Air source heat pump does not have problems with outside temperature, most will keep COP >2 and 50+ output (R32, R290) even in less that -10 outside.They have problem with humidity. With outside temperatures from -5 to +5 COP will drop to <1, because outside evaporator freeze in minutes. Defrost cycle use internal heat to melt the ice.Water source heat pump will need at least 1 to 3 kW to pump water from a well. If water level fall too deep, heat pump will stop completely. Sand and mud from a well will clog filters very fast. These filters will need cleaning every few days for first year ot two until a well settles down. Also a well water temp must be at least +7 and have 2 to 5 m3/hour capacity in winter.Heat pumps compressors have expected life of about 7 to 10 years. Anyway after 5 years they will change refrigerant type and current compressors will be not available as spare part. So be prepared to have another 20k+ euro for new heat pump in about 7 years.Make an simple calculation: If heat pump cost 20k euro to install and need to heat 6 monts/year:For 7 years: 20000/42 = 476 euro/month + electric bills.For 10 years: 20000/60 = 333 euro/month + electric bills.

author: Kleinstein
author_rank: Super Contributor
timestamp: February 17, 2024, 10:57:48 am
content: The heat pump can work well when it is not very cold. So it could make sense to keep the wood burner as an alternative and support for the few very cold days, when the heat pump is not working that well and high temperatures are needed. In a combination a air - water solution likely makes more sense. The main advantage of the geothermal heat pump is a more even temperature to start with. This is good for the few cold days, but bad for the not so cold days.For the ground heat pump it really depends on the local conditions. The ground and available area can effect the costs a lot. The COP also changes with the size of the system and over the year, when the ground cools. On may have to expect the ground to reach freezing - without it the capacity is relatively limited.Some upgrades to the house can make sense, to lower the needed temperature from the heat pump. This could be as little as fans under the radiators that are borderline sized.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 17, 2024, 11:04:27 am
content: Wow, these are grim perspectives.I'm not someone who stands on one nights ice and do in depth research. That is why I asked this question here. I know this forum is more about electronics, but heat pumps are very technical too.For geothermal there are basically three variants. Horizontal capture with a couple of long loops buried in the ground, vertical with closed loops in drill holes up to 100m deep and vertical with a well. The latter indeed needs filtering and have sufficient flow to sustain the pump. It does use a separate water pump to bring up the water but has, according to the documentation, a higher efficiency with the heat pump.With air there is indeed the freezing of the evaporator that needs energy for defrosting. When resistance heating is used the COP will drop dramatically. But the latter seems to be optional in many systems.The house is reasonably well insulated. Average annual energy consumption for heating the house, based on my experience with the wood burner is ~16500 KWh. Worst day average this season is about 8.75 KWh. It is a big house with 240m2 of living surface.

author: Zero999
author_rank: Super Contributor
timestamp: February 17, 2024, 11:08:38 am
content: What's the mean temperature in the coldest months?My understanding is, the problem with heat pumps is are least efficient, when the air temperature is above freezing and it's humid. Moisture condenses on the evaporator and freezes, causing it to ice up. This can be alleviated by only running at night, when its colder, but much of Southern and Western Europe's average overnight lows in the coldest months are still above freezing.Perhaps a more efficient wood gasifier system is a good idea? Wood is a very dirty fuel, which releases lots of nasty carcinogens such as benzine and particulates, when not completely burnt. Gasifier systems pyrolyse the wood. to release flammable gases, which are cleaned before burning.

author: Gyro
author_rank: Super Contributor
timestamp: February 17, 2024, 11:13:18 am
content: Skill Builder channel has a nice down to earth approach, with a healthy hint of skepticism about government initiatives. He has recently done a series of videos on viewer 'John', who has been through a nightmare with his heat pump and enough maintenance and other bills to have paid his energy costs for years to come. If you get them in chronological order, it covers the initial problems and then analysis by several more experienced companies and solutions.I have included the search term 'Heat pump John'...https://www.youtube.com/@SkillBuilder/search?query=Heat%20pump%20JohnP.S. He also has a couple of videos on wood burners.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 17, 2024, 11:23:52 am
content: Quote from: Zero999 on February 17, 2024, 11:08:38 amOver here based on my own measurements for this season the lowest average is about -4 degree and the total somewhere around 5 or 6 degrees Celsius. (day and night average) It is not as cold anymore and we hardly see snow. Last winter season maybe one week or so, and this season up till now none.Quote from: Zero999 on February 17, 2024, 11:08:38 amPellet burners, I think, are based on this principle and will be cleaner then what we have, but these installations are very expensive. They also need regular upkeep like removing ashes and still produce fumes. A problem is that when we use our extractor hood the fumes are drawn down the chimney of a small wood stove we have in our kitchen/living area, despite the other ventilation holes in the house. This chimney is sitting right next to the one from the basement for the big wood burner and would have to be used for the pellet burner too.

author: Zarhi
author_rank: Contributor
timestamp: February 17, 2024, 11:26:58 am
content: Quote from: Zero999 on February 17, 2024, 11:08:38 amAir humidity does not drop to 0% below 0 °C. Evaporator temperature is below -30 °C and will build ice even in -10 °C "dry" air.

author: nctnico
author_rank: Super Contributor
timestamp: February 17, 2024, 11:55:37 am
content: Quote from: pcprogrammer on February 17, 2024, 08:46:18 amHow about installing underfloor heating? That way you don't need the water to be very hot and you get better efficiency from there on.And how about getting an LNG tank and use a natural gas burner? It sounds like you are retired so you don't need a solution which lasts for another 50 years.Either way, I'd look at a solution which is most commonly used in your area. That way availability of parts and maintenance will be way better compared to getting some kind of outlandish setup which nobody knows about. As far as my experience goes, installers of heating systems know less than zero about what they are doing.

author: fourtytwo42
author_rank: Super Contributor
timestamp: February 17, 2024, 11:59:59 am
content: I can tell you from actual experience of an "ECO" office building heated by ASHP that in winter here in the UK they are useless!! Meaning they spend a huge proportion of time in energy gobbling "defrost mode" defrosting the outdoor unit, not just once but all day on a cold day, so just when you need the heat there is none.Whats wrong with a gas or oil condensing boiler ?I wouldn't touch an electric boiler with a bargepole, those poor people in Scotland who were experimented on with the things complained loudly of horrendous electricity bills.Don't be tempted by fancy electric tariffs either, here today, gone tomorrow.You might call me skeptical but if I am to make a large investment and trust my comfort to something I investigate very thoroughly, especially if they are being pushed by politicians whom as we all know are not adverse to a bit of industry/expert-crank lobbying

author: Zero999
author_rank: Super Contributor
timestamp: February 17, 2024, 12:09:21 pm
content: Quote from: Zarhi on February 17, 2024, 11:26:58 amIt's true that air below freezing still contains some water, but going from what I've read, it's much less of a problem, when it's below freezing, especially once the ground is frozen, so no water can evaporate into the air. I've noticed that in winter, when the wind is blowing from the east, off the cold continent, the air is do dry, ESD is a problem and I feel my sinuses drying up.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 17, 2024, 12:13:28 pm
content: Get a sensibly priced monoblock (refrigerant is sealed in at factory, only water pipe connections are needed) and have a plumber/electrician install it for you. For example Swedish company ES imports Chinese Amitime heatpumps. Mine, a 9kW unit cost less than 3000EUR with all the accessories I had to get. I installed it myself. Panasonic also does some Monoblock units which are not more expensive.By all means leave the existing burner. You can choose to use it during the coldest days, and it's a good idea to have a spare system. I left my dual oil-wood boiler and keep using it; the 9kW ES/Amitime monoblock reaches approx. COP=1.5 around -15degC outdoors / +40degC water; if this condition lasts longer than a day or two, then I switch to oil/wood.People in much colder climates use heatpumps no problem. Netherlands is obviously totally fine. The only exception is if your distribution system (radiators) is super crappy (i.e. small surface area) i.e. requires high water temperature already in modest weather. You may be able to replace some radiators for bigger ones. That's what I did, radiators are not expensive.Finally, just normal air-to-air units might be a better idea, especially if your home has large central "open concept" area. Models designed for heating in colder environments, not the cheapest ass "mostly for cooling" units. A good one is still below 1000EUR. They don't have the problem of high distribution temperature, and you can also use them for summertime cooling. You can probably get them for less than 1500EUR installed so if air-to-water guys give ridiculous quotes over 15000EUR, you could get five(!) air-to-air units for half(!) the cost, and get better COP!I would guess actual SCOP (annual COP correctly weighed for more consumption during coldest months, calculated simply annually_produced_heat / annually_consumed_electricity) for Netherlands is at very least 2.0 for super crappy mini radiators, 3.0 for OK-ish radiators and 4.0 for underfloor or fan coil distribution.There are two simple questions for you:* What is the coldest "not unusual" temperature in your region which you experience every winter, for more than a few hours a day, for more than a few days? E.g. something that lasts for a week or two (nearly) every winter,* In said weather condition, to maintain comfortable room temperature, how hot is the water flowingintothe radiators - you can measure it using infrared thermometer (bonus point for measuring the water temperature as it leaves the radiators)Answers to these questions vary so much it's hard to guess.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 17, 2024, 12:16:01 pm
content: Quote from: nctnico on February 17, 2024, 11:55:37 amWe already have underfloor heating and low temperature radiators in the rooms that don't have underfloor heating. That is not the issue. My 8 years with the wood burner system with a 5000 liter heat storage has shown that on the really cold days the system wants ~55 degree Celsius coming from the heat storage mostly for the radiators to keep the rooms up to set temperature. On warmer days it can work with lower temperatures down to 30 degree Celsius.And indeed it does not have to last for 50 years. I'm 60 and the wife is 59, so another 25 or so, if we manage to keep living here.Down here a lot of fuel (diesel) is used for heating, but the government wants it gone, and we thought the sale of these type of burners had stopped in 2022, but one of the installers told us the regulation has been delayed.Gas could be an option, but it is not used much around here.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 17, 2024, 12:18:39 pm
content: Quote from: Zero999 on February 17, 2024, 12:09:21 pmA practical example: my ES/Amitime 9kW unit runs defrost cycle around 20-25 times a day with temperatures around 0degC. This is the worst case. At -15 .. -20 degC, the heatpump easily makes 2 - 3 hour stretches so just around 10 defrosts per day, even when the RH is the same or even higher.If the heatpump implements detection of frost properly, defrosting is not a dealbreaker even in very cold environment, because the situation indeed gets better as it gets colder. There are stories of bad products which overdetect the need of defrosting, e.g. doing it every 40 minutes in -20degC, which then totally kills the COP.

author: nctnico
author_rank: Super Contributor
timestamp: February 17, 2024, 12:20:33 pm
content: Quote from: pcprogrammer on February 17, 2024, 12:16:01 pmWell, going for a diesel burner is a no-brainer then. The French will be hell-bound on keeping those systems as these are likely cheap to operate, so they will be around long enough for you.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 17, 2024, 12:22:21 pm
content: Quote from: pcprogrammer on February 17, 2024, 12:16:01 pmGiven underfloor + low temperature radiators, your situation is optimal for air-to-water heatpump.I would also consider utilizing your existing energy storage system to benefit from varying market prices of electricity (if such contracts are available in NL, I don't know). I have 1200-liter storage and would kill to have your 5000-liter reservoir! That's a huge asset on its own.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 17, 2024, 12:34:58 pm
content: Quote from: Siwastaja on February 17, 2024, 12:13:28 pmTo answer these questions I have to search my backed up databases from the heating system. I have a Raspberry PI measuring and controlling the whole system. All the pipes have sensors taped to them. Not super precise but it gives insight in what is going on. At the moment two sensors are dead so the readings of my departure of the heat storage and after the mixing valve are gone, but these don't matter that much.I have a mixing valve in the system to reduce the >85 degrees Celsius the storage can reach, down to the needed temperature. There is a guard system to make sure the underfloor heating stays below 40 degrees Celsius.Attached is a screen capture of the web interface I have for it.

author: watchmaker
author_rank: Unknown
timestamp: February 17, 2024, 12:35:50 pm
content: The cost equations differ across the world. I am in the US, about 150 miles north of Boston. Here in New Hampshire electricity rates are among the highest in the US.Oil is also not cheap and then there is the fossil fuel thing.We decided to install a solar system for our electricity this coming summer. In the interim, we installed a heat pump in late 2022. It is used in conjunction with our oil-fired hot water forced-air furnace.While of course our electricity went up, our oil bill was more the halved. We have noticed the heat pump still contributed even at -3 degrees F.Also, unlike the old heatpumps (had one in the 90s), this system is very comfortable. We installed a humidifier with it and keep the house at 40% so we are happy at 62 degrees F.Hope this helps.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 17, 2024, 12:47:44 pm
content: Quote from: pcprogrammer on February 17, 2024, 12:34:58 pmNice, I would recommend this process:* Buy monoblock heatpump,* Connect monoblock's water inlet in parallel with the radiator/infloor heating return pipe, the one that connects to the bottom of the 5000l tank,* Connect monoblocks water outlet near the top of 5000l tank.* Normally, let the heatpump control the water output temperature based on curve from outdoor temperature, and force the mixing valve fully open to avoid loss of temperature (which costs you some COP)* When transitioning to wood, just shut down the heatpump and let the mixing valve gradually close to regulate the water temperature,* When transitioning back to heatpump, just turn it on and let it start heating once the big tank cools down to the setpoint of the heatpump. Let the mixing valve open and force it fully open again.This is how I do it.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 17, 2024, 12:50:01 pm
content: Quote from: Siwastaja on February 17, 2024, 12:22:21 pmHeating 5000 liters with my 38 KWh wood burner takes between 10 to 12 hours and on the cold days it only lasts for 36 hours coming from ~85 down to ~30 degrees. With a heat pump you probably won't reach much higher then 55 to 60 degrees and it will have to work the whole night to get there. It would save on the high charge days though. We live in France, but are Dutch and here we have a setup from the EDF called tempo. On 22 days in the winter electricity is 3 times the normal price during the day. On 44 days the reduction is about 20% during the day and on the remainder it is about 30% reduction. During the nights there is always a reduction but varies depending on the type of day ranging from ~15% to 40%.But keeping on the wood burner for the 22 expensive days is not an option for me. I'm struggling with it as is and it is not going to get better unfortunately. That is the whole reason for the change.

author: nctnico
author_rank: Super Contributor
timestamp: February 17, 2024, 01:02:03 pm
content: Quote from: pcprogrammer on February 17, 2024, 12:50:01 pmHence my suggestion to go for the diesel burner. You can install a high-tech system right now but who is going to fix it in 10 years from now? You might not be able to do this yourself. If most of the neighbours have a diesel burner then there will always be somebody nearby who can at least take a look at it when something is wrong with it.Also, are there ways to improve the insulation of the house? Replacing regular double glazing with HR++ glazing makes a massive difference. I'm in the process of doing that. Another system high on my list is a balanced ventilation system which recovers the heat which otherwise just blows out of the house. I expect this to reduce heating costs and improve comfort by a large margin.

author: Zero999
author_rank: Super Contributor
timestamp: February 17, 2024, 01:08:10 pm
content: Quote from: Siwastaja on February 17, 2024, 12:18:39 pmDoesn't that completely kill the performance?I would have thought icing up will be worst around 5°C, which is very close to the average temperature, in the coldest month, in the OP's location. At higher temperatures, then the heat can be removed from the air without freezing.A ground source hear pump is probably more optimal in the OP's climate but it depends on the geology.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 17, 2024, 01:12:33 pm
content: Quote from: nctnico on February 17, 2024, 01:02:03 pmThe diesel burner is not a very good option due to the smell and it is also expensive. Could probably get better quotes for it then the one we got, but still.Upcoming trend is heat pumps. We see them getting installed more and more around here. Mostly used is fire wood. For as far as I know already 4 air to water heat pumps and maybe two houses with a diesel burner. This is a very small village with ~100 inhabitants.Edit: The house has HR double glazing for the new build and probably mostly standard double glazing in the old part. We build the biggest part of the house ourselves. Walls and roofs are insulated with 75mm fiberglass insulation.The question here is which of the two heat pump solutions would suit us best. Air to water or ground to water.So far the disadvantage of an air to water system seems to be the freezing of the evaporator and a lower seasonal COP.How about maintenance of an air to water unit. Our house is surrounded by trees so a lot of leaves to deal with. Will this be a problem for the ventilator in the unit.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 17, 2024, 01:30:54 pm
content: Quote from: Zero999 on February 17, 2024, 01:08:10 pmThat also is the opinion of one of the three companies we asked for a quote. But how objective is his opinion, since the company specializes in geothermal. The first was resolute diesel or pellets is the way to go, because that is what he does most. The third opted the air to water solution, because again what they do most.Hard to find good objective information on the subject. We are leaning towards the geothermal solution. We know it is expensive and will never see a return on investment, but living costs money and comfort is worth it, to us at least.

author: coppice
author_rank: Super Contributor
timestamp: February 17, 2024, 01:41:17 pm
content: Quote from: pcprogrammer on February 17, 2024, 01:30:54 pmJust beware of people selling low cost ground source heating. If you take the heat from a big enough underground reservoir it can work well. However, to keep the price and installation disruption low a lot of people will offer solutions that get too much heat from a small area. That may work great for a year or two, but you need to worry about the long term, and whether the heat you draw from the ground can be replenished. If you have hot summers and cold winters things even out from pumping heat in both directions, but it doesn't sound like you want to pump any heat down the hole.

author: RoGeorge
author_rank: Super Contributor
timestamp: February 17, 2024, 01:51:30 pm
content: Quote from: pcprogrammer on February 17, 2024, 08:46:18 amNot really. Heat pumps require significant amounts of electricity for the compressors (to pump the heat) and defroster, or else they can not pump at all the heat from a lower temperature to a higher one.Classical stove OTOH, does not require electricity, except maybe for a small recirculation pump, but that's for comfort only, it is not essential. The recirculation pump only needs insignificant amounts of electricity, it only moves water. Heat comes entirely from the combustible itself (wood), and the flow from heated water to room happens naturally. The small recirculation pump can be eventually removed by a clever design, or can be actionated ocasionally by other means (backup batteries, or a small oil-based generator, depending on how long the power surge lasts).Heat pumps do not work at all withoutsignificantamounts of electricity, unless you live nearby a hot water geyser (AFAIK there are none in France). Otherwise, a heat pump requires way too much electricity to be supplied by a battery, or by a local backup generator.Another thing to consider if you live in France, you should estimate the future cost of electricity (for heat pumps) at much higher price then it is now.So far France has had plenty of cheap electricity coming from nuclear power plants that were fueled by relatively cheap Uranium from Africa. The situation in Africa has changed recently, and nuclear fuel will become expensive. Many will have to shut down. This will impact not only France price of electricity, but the entire EU. Do not assume nuclear power plants can be replaced by wind or solar. When compared with nuclear, wind and solar are an absolute joke.

author: nctnico
author_rank: Super Contributor
timestamp: February 17, 2024, 01:52:40 pm
content: Quote from: pcprogrammer on February 17, 2024, 01:30:54 pmAFAIK geothermal wells need to be re-drilled every 15 years or so. I might be wrong, but make sure to check how long a drill hole can be used.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 17, 2024, 01:59:58 pm
content: Quote from: coppice on February 17, 2024, 01:41:17 pmYes, also something that is on our minds. I asked the sales person of one of the companies what the expected life time of the source would be, and if pumping heat back in the summer is needed. He said no. He himself has a system for 20 years now and still going strong he said.On the net searching about this says "these sources are not unlimited" but they don't mention what the average time is before it is depleted.With the system he offered it is possible though to cool the house in the summer and pump back heat into the hole, but it is active cooling, which means more electricity consumption. And it only works with the underfloor heating, and these rooms don't need that much cooling. The upstairs bedrooms can run up to ~29 degrees Celsius which is hot, but these only have the radiators.Attached are some pictures of the current wood burning system and the control.I attached servos to the burner to control the air inlet valves. Ended up replacing them with brush less high torque servos. The smaller ones did work, but the motors wore out quickly.The 5000 liters is divided across two tanks. Had to modify them because at first I used PVC sewage pipes to prop up the secondary heat ex-changer. It collapsed due to the long term exposure to >80 degrees water. Now it is held up with copper pipes and wire.Every September we throw down ~22m3 of wood and stack it like shown on one of the pictures. In January another 3m3 follows. Hard work.Also had to redo the controller after lightning damage. Now fully opto isolated between the controller and the sub stations.

author: Zero999
author_rank: Super Contributor
timestamp: February 17, 2024, 02:03:02 pm
content: Quote from: pcprogrammer on February 17, 2024, 01:59:58 pmSimple: use a solar thermal system in summer, to replenish the heat. The pumps can be solar powered.Quote from: nctnico on February 17, 2024, 01:52:40 pmI wasn't thinking of a well, but a large coil of pipe buried in the land next to the house i.e garden/yard. It obviously needs to be large enough to collect sufficient heat. The average annual temperature, including summer and whether it's also going to be used for air conditioning might make a difference. I suppose, if you live in an area with cool summers and don't need air conditioning, you could use solar for hot water in summer, which will allow the ground to warm up before winter.

author: coppice
author_rank: Super Contributor
timestamp: February 17, 2024, 02:04:15 pm
content: Quote from: nctnico on February 17, 2024, 01:52:40 pmThat's problem problem I described above. Too much heat being drawn from too small an area, faster than the replenishment rate, eventually results in a useless source for the heat you need. Its avoidable, but it may require considerable extra up front costs and disruption to put an adequately sized system in place. I'm sceptical of the calculations people use. They try to make it a simple one size fits all approach. The ground varies a lot from place to place, and clearly heat flow rates are going to vary a lot too.

author: coppice
author_rank: Super Contributor
timestamp: February 17, 2024, 02:12:52 pm
content: Quote from: Zero999 on February 17, 2024, 02:03:02 pmFew people have enough area available for such a system, so most people have to go deep rather than wide. They still use pipework, though.Would it be better to replenish the underground heat with solar thermal, or solar panels driving the heat pump?

author: coppice
author_rank: Super Contributor
timestamp: February 17, 2024, 02:16:33 pm
content: Quote from: pcprogrammer on February 17, 2024, 01:59:58 pmI would avoid using these systems for cooling, especially if you have humid summers. The condensation on the radiators can be a nightmare for mould formation, even if they are basically wipe clean surfaces. Its hard to deal with mould on the rear. A cool floor can be very uncomfortable, an increasing condensation on a carpet is a really bad idea.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 17, 2024, 02:16:57 pm
content: Quote from: coppice on February 17, 2024, 02:04:15 pmOur terrain, even though it is ~1Ha, does not have enough grass land to put a horizontal system in. So we need vertical drill holes. We are waiting for the second quote on this, but the first specified that two holes of 85m deep would do. They have to be spaced out at least 7m if I understood him correctly. (French and me does not go together that well. I speak it a bit but understanding is more difficult. The wife is better at it but gone when it becomes technical)

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 17, 2024, 02:22:15 pm
content: Quote from: coppice on February 17, 2024, 02:16:33 pmThe summers are indeed humid. The radiators are of the kind sold by this companyhttps://jaga.co.uk/lst-heating-radiators/tempoWhen cooling they should remain cutoff of the system. The floors with heating in them are covered with wood. 14mm of chestnut. Temperature should not be set below 18 degrees to avoid condensation, but I'm not to keen on it anyway.

author: Zero999
author_rank: Super Contributor
timestamp: February 17, 2024, 02:26:19 pm
content: Quote from: coppice on February 17, 2024, 02:12:52 pmI honestly don't know. Solar thermal doesn't involve running the heat pump and the associated wear and tear, but unlike photovoltaic, it can't be used for other purposes.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 17, 2024, 02:30:34 pm
content: Quote from: Zero999 on February 17, 2024, 02:26:19 pmIt would also require special pluming on the side of the source. At least a three way valve to switch over to the solar panels and a separate pump to circulate the water. The question is if it is worth it.The wife found on the net that a source like that can be used for up to 30 years, so good for us

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 17, 2024, 03:13:37 pm
content: Quote from: RoGeorge on February 17, 2024, 01:51:30 pmEverything can change in the future for sure. Fossil fuels also get more expensive. Fire wood also gets more expensive.If global temperatures keep going up we might not need heating anymore, and so on. Not realistic and makes living harder if for every decision you start to think about the future and what it will bring.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 17, 2024, 03:31:14 pm
content: Quote from: pcprogrammer on February 17, 2024, 12:50:01 pm5 m^3 * dt=55degC is whopping 320kWh of energy, so 213kWh per 24 hours or 9kW average thermal power. Sounds like you have a pretty large house, or poor insulation. To compare, I need 5kW thermal to maintain +21 indoors at -25 outdoors, but then again I'm only heating some 120 square meters, maybe your home is bigger.QuoteYou are correct - with a heatpump, storing energy by increasing dt means immediate compromise in COP, so you get the best efficiency and least energy used by not storing but running continuously. Well with large enough storage, you could run the heatpump during higher air temperature then use the produced heat during lower air temperature thus increasing COP. But realistically if the outdoor temperature varies by 10degC during 24hrs, and if you then have to increase storage temperature by 10degC to get the energy stored during 24hrs period, you have already lost the gain. If you have to increase by 20degC, you are losing on COP. For that to make sense, you would need a pricing scheme where hourly prices have large enough differences. The problem is, lower prices at night coincide with lower temperatures at night, so in the end it might be best to just let the heatpump run on its own curve algorithm without any storage; during night when it's colder the thing ramps up, and that coincides with cheap hours.Here we usually have a price peak at 7-8 am and avoidingthatone brings significant savings without need for any large storage reservoir.QuoteI hear you. Personally I have found it's much easier to struggle with something for a few weeks than all the time, but 22 days is quite a lot actually. It's still a good idea to keep the existing system because it will help you when that record cold which only happens only every 5 years hits you and the heatpump is approaching COP=1. It you then keep burning for a week or two you have dodged the bullet, without having to sacrifice your whole life to burning wood - a hobby for some.Realistically, the heatpump would be running resistive aux heating in most extreme conditions, which is OK.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 17, 2024, 03:45:04 pm
content: Quote from: Zero999 on February 17, 2024, 01:08:10 pmOn my unit, I have never seen freezing at +5degC (well on low power level, an occasional small stripe on the evaporator, but nothing that grows enough to require a defrost cycle), need for defrosting starts at around +3 degC and gets worst at around 0 degC then gradually better at colder temperatures. (Of course "better" is quite relative word, more frequent defrosting at coldest temperatures would be catastrophic for both average output power and COP.)Even at 0-ish (0, +1) degC, in most humid conditions ("British weather") the need for defrosting actually decreases or even completely disappears, because so much energy is released by condensing the water it keeps the evaporator clean of ice. It basically rains water under the machine in such conditions and COP is great.QuoteOP's climate is, I think, pretty good for air source heatpumping. Even here in much colder climate, many choose air source, but sure, here ground source wins hands down. As I said earlier, given OP's specifications, I believe air-to-water unit would come close to SCOP of 4. 100% sure it will significantly exceed 3.0. With ground source you would get to maybe 5.0. In such Middle European conditions, days of +5degC or so dominate in heating bill. Optimal for air source. Ground source would give only slight advantage.Quote from: nctnico on February 17, 2024, 01:52:40 pmHere we have a lot of experience of ground source drilled in many different soil types over 30-40 years or so and this kind of problem is rare. Maybe if you have some seismic activity then quite obviously it can damage the plastic pipe that's put into the ground, but usually people assume the lifetime for the hole is at least 40-50 years.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 17, 2024, 03:58:13 pm
content: Quote from: pcprogrammer on February 17, 2024, 01:12:33 pmI have a cherry tree close to my outdoor unit. Expect to have to remove a leaf or two every now and then stuck on the evaporator coil, or in the bottom tray. Not a big deal IMHO. Otherwise it's been maintenance-free. Given your climate plus relatively low distribution temperature I would definitely bet on the air-to-air unit. Some people have bad experience but it's based on some specific brands/models being bad, so do your googling before committing to purchase.On English-language websites like this, people sometimes make defrosting sound like a big issue. But it's normal operation, not a problem. The only problem might be finding real-world data for a certain unit so you have to rely on specifics you hear from others. In the end, ignoring some random problems like a flawed defrost logic on some Mitsubishi Electric LN series air-to-air units, most heatpumps perform quite similarly, more expensive brand doesn't necessarily give you any better COP. You get the best COP by minimizing distribution temperature, regardless of brand, and this you have already done, so. Just ignore totally unsuitable lowest-tier units designed for the warmest climates (e.g. basically swimming pool heaters) and you should be fine even with a cheap unit. Presence of bottom tray heater and compressor heater already communicates the intended usage in cold environment.

author: baldurn
author_rank: Regular Contributor
timestamp: February 17, 2024, 05:00:38 pm
content: I propose air to air units for the upper floors. It will be 1500 euro per room. Keep the radiator for redundancy. However with this you no longer need 55 degree hot water and can choose a more reasonable temperature for the floor heating downstairs. You will get optimum COP because the air to air units only need to deliver air at the temperature needed in the room.In the summer you can use the units for air conditioning.My other advice is to oversize somewhat. The endless cycles of defrosting can be attributed to undersized systems struggling to get the job done. I have one air to water and two air to air. We have had no trouble this rather cold winter.Regarding the noise, you will not notice it indoors. But you will outdoor. Even the more silent systems are not 100% silent. This is of course worse on the days you do not want to be outside however. One advantage of the geo thermal system is no noise at all.Indoor you often have another type of noise. Radiators are not completely noise free if you are sensitive to that. The air to air units also have indoor fan noise. I am not too bothered about it, but your milage may vary.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 17, 2024, 05:15:18 pm
content: Quote from: baldurn on February 17, 2024, 05:00:38 pmIf the underfloor heating is downstairs and radiators upstairs (I missed that but did not read too well, sorry for that), then this is pretty good advice: even if the radiators are of low temperature type, they still need higher temperature than the underfloor loop. E.g., in worst cold conditions, maybe 30degC for the floors, 40 for the radiators.Then doing a hybrid solution and getting smaller air-to-water unit for the floors, and air-to-air units for upstairs would make sense. The air-to-water unit must deal with the higher of the two temperatures, so if you only use it for the lower temperature circuit you are getting better COP all the time. You also get more power output from the same unit with lower temperature, since the power limitation is actually input power limitation! And then, given that you are only heating part of the house, smaller unit will do, and the air-to-air units would then take care of the upstairs separately.For summertime cooling, upstairs is usually where the heat is the worst anyway so most cooling needed there, especially if bedrooms are upstairs. Additionally cold air easily goes down so you need to just to open a door to the stairway and some cool air goes down so you might manage without cooling solution downstairs. Air-to-water heatpump can provide a little bit of cooling through the underfloor circuit but it must be non-condensing meaning it will increase RH% by reducing temperature without reducing absolute humidity. Therefore having air-to-air units is a good idea as they offer real dehumidification, in humid-hot summer conditions (I don't know if that's a problem for you, though).

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 17, 2024, 07:13:52 pm
content: Quote from: Siwastaja on February 17, 2024, 03:31:14 pm

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 17, 2024, 07:23:33 pm
content: Quote from: baldurn on February 17, 2024, 05:00:38 pmI'm very sensitive to noise. I can hear the rumble of the underfloor heating in my room, but it is not loud enough to be hindered by it. A blowing fan is a different story. We have an air purifier bought for relieving the wife her allergy that turned out to be something else, and I could not stand the noise of it.So no air to air units for me.After we get the quotes from the last company we had around we will make a weighed decision. I do appreciate the specific input on the core of the question.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 17, 2024, 07:30:23 pm
content: Quote from: Siwastaja on February 17, 2024, 05:15:18 pmFor us the least invasive solution is one with a heat pump based on water on the house side. Be it air to water or ground to water. All that is needed is to bring a couple of pipes into the basement and connect it to the existing system.The wife will kill me if I suggest to have work done in the upstairs bedrooms to add an air conditioning unit above her bed. Se is not to trilled about either the mess of the work being done and the noise of the finished system once in place.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 18, 2024, 07:26:15 am
content: If you are very sensitive to noise, even the outdoor unit of air-to-water heatpump could be a problem for you. Definitely not a problem for me, but when it's running near full compressor speed (85 or 90 Hz), Icanhear it in the closest by room, even when it's free-standing and not wall mounted (which you want to avoid). Install as far from bedrooms as possible, unless it becomes too big of a compromise for pipe lengths (refrigerants for split units, water for monoblocks; in both cases, too much length is a compromise you don't want to make). I chose my install spot based on minimized pipe length right next to the boiler room of the basement.

author: m k
author_rank: Super Contributor
timestamp: February 18, 2024, 07:54:06 am
content: Water out monoblock has a problem if electricity goes off when temp is below freezing.Steady 9kW of heating energy is quite a bit for a house, even for non-optimal cases.I'd put up a wireless heatpipe temp sensor network.Our more industrial era general insulation material used to be glass wool, before that it was planer chips or saw dust.Regular roof thickness was less than half a meter.Now organic blow wool is many times added so that total thickness is more than 1/2 meter.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 18, 2024, 08:11:44 am
content: Quote from: Siwastaja on February 18, 2024, 07:26:15 amThat is why we are leaning more and more towards geothermal. The fear of noise.According to the specifications the De Dietrich GSHP 12 MR-E produces about 56dB. Our vacuum cleaner, according to its specifications, produces 66dB. We tested with it running full speed in the basement, where the heat pump would go, and I can not hear that in my room. Another one that produces more dB's with a higher pitch in it, I could hear.I know that the type of sound can differ and resonance can play a role, so part of the decision making will be a visit at a working installation.One other thing I wonder about in the specifications is the current being drawn from the net. The pdf I found for the De Dietrich is >10MB and in French and can be foundhere.It states "Intensite nominale" 27.9A which would mean ~6.6KWh if the cos phi is 1, which it most likely is not, but still much higher then the "Puissance électrique absorbée" of 3.1 KWh. The seller stated it to be the startup current, but the specification only states for that "Intensité de démarrage" <30A.My issue with it is that we have a 9KVA mains supply and the "Linky", our intelligent electricity meter, might cut us off when the current surpasses the 45A it allows. With a 2KWh water heater, a refrigerator, a freezer and the heat pump possibly running at the same time might be enough to do this.Sure I can always change the subscription for a higher one, just don't want to be surprised by a cutoff in the middle of the night.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 18, 2024, 08:22:20 am
content: Quote from: m k on February 18, 2024, 07:54:06 amThat is a good point, and this would not be the case in the setup one of the parties is offering. It will not be a monoblock but one with a unit inside the house and only the coolant running through the external pipes, so no risk of freezing.Quote from: m k on February 18, 2024, 07:54:06 amThe 9KWh is only on the coldest days. At the start and the end of the heating season the 5000 liter tank lasts more then a week.My system has 80, one wire based, temperature sensors for monitoring every pipe, room, storage and control part of the system.

author: kripton2035
author_rank: Super Contributor
timestamp: February 18, 2024, 08:24:56 am
content: I would add some solar panel array to a heat pump, and also look at the geothermal one...with an hybrid inverter, it could withstand the power surge you're describing.

author: RoGeorge
author_rank: Super Contributor
timestamp: February 18, 2024, 09:25:52 am
content: Quote from: pcprogrammer on February 17, 2024, 03:13:37 pmThe difference is, one can easily store wood for 10-20 years in a barn in own backyard, or oil in an underground reservoir. Electricity can not be stored in large enough quantities. Don't know the price of wood in France, but I guess the upfront money needed to install heat pumps should be enough to buy now all the fire wood needed for the next 25 years.Then, you'll have much smaller electricity bills for the next 25 years, plus you won't care about any future solar storm that might knock down the power grid (this last argument is only because you brought global worming into discussion).I've spotted above "9kW". Don't know the law in France, but here in Ro, for that power one would need to change the existing connection to the grid from single phase mains AC (must stay under 5kW or so for a household connection) to mandatory 3 phase AC (for more than 5kW installed power). Might need some costly modification for the electric wiring of the house, and a new/different supply contract with the electricity provider. Also, here the 3 phase electricity is regulated at higher price (3 phase and bigger installed power is usually needed for business/commercial only, thus the different pricing, plus the power factor will be considered, too, 3 phase customers have to pay for both the active power, and the reactive power, as opposed to single phase users that only pay for the active power).Strategically, replacing a wood burner with a heat pump only brings big upfront costs, increased running costs, plus some other minor inconvenience like noise, etc. The worst is, from that moment on, you'll depend very strongly of the power grid, which is not under your control. One can buy wood from 10 different places, but can not have 10 connections to 10 different power grids. Won't insist bringing more argument.In conclusion, I wouldn't replace a wood burner with a heat pump, but I might be wrong.Whatever your choice will be, wish you the best.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 18, 2024, 09:45:54 am
content: Quote from: m k on February 18, 2024, 07:54:06 amThis is a myth. It's almost never a problem, only in some special cases. Worth thinking about of course. If you have very long horizontal pipes and very little or no storage capacity it can be a problem. For example in my setup, I regularly just cut the power from the heatpump during -30degC. The heat exchanger stays at the storage tank temperature due to natural convection in pipes.Many otherwise good systems are compromised by installing completely unnecessary extra glycol loops and extra heat exchangers in irrational fear of monoblock freezing. Trade unions hate monoblocks as they require no professional refrigerant work, so they spread this kind of FUD.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 18, 2024, 09:57:43 am
content: Quote from: RoGeorge on February 18, 2024, 09:25:52 amYou most likely are wrong. In mildly cold climates the SCOP of heatpump is high enough that you would need to have nearly free source of wood, or unbelievably expensive electricity for this to be true.However, if you have an existing system for burning wood / wood pellets / gas / oil, then the cheapest solution is a hybrid, i.e. add a smaller heatpump in parallel, to take care of the low hanging fruit conditions, which for especially middle european climate are plenty.But the OP wants to get rid of the manual work of burning wood, completely or nearly completely. Then the cost shifts upwards from this optimum "hybrid" solution, but probably not much, and unless they had access to really cheap wood, the final bill will be smaller than with wood-only.Wood only is absolutely stupid because large part of year heatpumps produce excellent amounts of heat with little electricity, and there are times clean electricity is plentiful in the grid. The efficiency of burning wood is always the same, say 70%. Compare that to the varying efficiency between 100% and 500% of the air source heatpump.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 18, 2024, 10:38:56 am
content: Quote from: RoGeorge on February 18, 2024, 09:25:52 amNot completely true. Wood suffers from decay and insects, and diesel / oil also has problems with long term storage.My argument about global warming was to emphasize the fact that when worrying about the future to much, it inhibits making decisions.Quote from: RoGeorge on February 18, 2024, 09:25:52 amNot an issue here in France. Have not looked into the max we can get on a single phase, but if needed a change over to three phase would not be that big a deal.Quote from: RoGeorge on February 18, 2024, 09:25:52 amIf it was not for my health, we would continue with the wood burner, no question about that. Running cost based on current wood price is a bit higher then the estimations for running on a heat pump, at least for the geothermal system, going on the data of the one supplier, and this is in line with my own calculations. For air to water it depends on the true SCOP that can be achieved, and may be on par with the wood or less. This is of course based on the current electricity prices.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 18, 2024, 10:47:13 am
content: Quote from: Siwastaja on February 18, 2024, 09:45:54 amOne of the issues with the internet is the amount of "misinformation" and often only the horror stories that give a very one sided picture of things.Same with inviting the "professionals" in for a quotation, they will preach for their own choir, and try to convince you that their setup is the best. So careful weighing of the information is needed.

author: m k
author_rank: Super Contributor
timestamp: February 18, 2024, 11:35:17 am
content: (knew I forgot some conditionals)I remember a case of natural circulation of heating water.Owner was a bit confused since he heard circulation bump rotating.It was summer and fuse was off.That free of pro installators is a thing here, non-R liquid is also part of it.Around circles, free wood is another argument.Sound noise is difficult, if you hear it you can't go back.Later you may hear it even if it's not there.Rotating parts have bearings.One night not so long ago I heard a small irregular whine of a bearing, it's gone now, for now.So single phase system.Close to 30A for compressor is a start-up of a difficult start-up.There is still over 15A after water heater, my guess is no blue moon for you.Your intelligent electricity meter is not instant, maybe somewhere is how long it can be over.Our windows are double elements with selective cover, no gas.(3rd glass is for ventilation)Old system had three separated glasses in two wooden frames.(nasty thing, middle one had a side of structure swappable rubber sealed metal frame)Changing them to triplets would be never paying back stylish.(assuming your heating history records are more than a moment)What about adding some sealing insulation above the current one on a selected spot.If it's really helping you should see the result during this spring.If you're cooling with heat pump the moisture is not a problem.(assuming here that doors and windows are mainly closed)(also that area of blown air is not a sump)The method of cooling, just a direction of heating, is sort of taking the containing water out.Problem it will be if that water has no managered route.All in all, it's actually pretty stupid to not have a heat pump in central Europe.Now it's also more stupid every year to not add a solar electricity feeding it.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 18, 2024, 12:21:46 pm
content: Quote from: pcprogrammer on February 18, 2024, 10:47:13 amMany of the problems people have with heatpumps are also things that are surprisingly easy to fix for technically oriented minds, but people who just want a complete solution which requires no tinkering are at the mercy of even small "bugs" of the commercial products or even small mistakes made in installation. And fair enough, of course if you buy an expensive system you have every right to expect perfection.I mean, I remember one case from this forum where the bottom tray heater was always on even with +10 degC outside and wasting >100W of power constantly, significantly reducing SCOP in modest climate where actual need for bottom tray heater is maybe 10% of year. I'm sure if you are having this kind of problem, being someone who is able to wire 80 temperature sensor around your house, you are also able to wire one thermostat or a relay controlled by your Raspberry Pi system. It's unbelievable that the manufacturer already has temperature sensor and relay to control the heater, but missed the 2-3 lines of code from the firmware to actually turn the heater off, but if you have to fix it afterwards, then that's what you have to do.Me, I have not made modifications to bottom tray heater but have seen it sometimes wastes more power than necessary. For me the gain is small enough I haven't bothered. The ES/Amitime heatpump seems to have a bug that the bottom tray heater sometimes stays on when the weather gets warmer, but that's easily solved by booting the thing, which you want to do anyway when the Windows CE control system gets slower and finally stuck

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 18, 2024, 12:45:23 pm
content: Yep bugs happen.When the installation is going to take place you can bet your ass that I'm watching every step they take. If I see a mistake I will tell them to fix it.Normally I would opt for doing the work myself but unfortunately I can't do that much anymore. Screwing something to the wall already wears me out and results in sore musclesOn the technical side wiring a simple relay to the existing system is no problem at all. Have to modify the system anyway to work with the new heat source.

author: coppice
author_rank: Super Contributor
timestamp: February 18, 2024, 01:19:31 pm
content: Quote from: m k on February 18, 2024, 07:54:06 amWhy is that a problem? Surely what is described as water is really, just like any car outside the tropics, water + anti-freeze.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 18, 2024, 01:26:46 pm
content: Quote from: coppice on February 18, 2024, 01:19:31 pmWater volume for a typical hydronic heating system is easily 100-200 liters even without any reservoirs, especially with large radiators or in-floor heating circuits. Many, like me, have extra 1000 liter or so storage tank. (OP has 5000 liters but from the pictures it seems to use pipe exchangers so doesn't count into the volume). Adding anti-freeze for the whole volume is surprisingly expensive. Also if you have domestic hot water heating through copper pipe heat exchangers like I do, then using toxic ethylene glycol anti-freeze is forbidden because a leak could theoretically cause a poisoning risk. Less toxic antifreezes are even more expensive. You would also need to safely remove the anti-freeze when you do any modifications or maintenance in the system, or have a leak. If you just use water, you can just drain and refill. So there are compromises and thus actually using anti-freeze is quite rare. If your house loses all heating for extended periods of time during the cold season, your water supply pipes, toilets, taps etc. would be bursting anyway, so the primary solution is to just avoid losing all heating for extended periods of time. Best bang for buck can be had by thermally insulating any pipes that run in iffy places, which does not prevent freezing but gives more time to react.

author: zilp
author_rank: Frequent Contributor
timestamp: February 18, 2024, 03:11:40 pm
content: Quote from: pcprogrammer on February 17, 2024, 11:04:27 amThose numbers don't add up. Assuming that you mean kWh (kilowatt-hours) rather than KWh (kelvin-watt-hours), 8.75 kWh per day every day would add up to only 3194 kWh per year.Quote from: pcprogrammer on February 18, 2024, 08:11:44 am... or are you possibly using kWh (unit of energy) when you mean kW (unit of power)?For one, you could use some sort of lock-out mechanism to stop heating while the water heater is active.But also: Have you looked into using the heat pump for your hot water as well? After all, if your heat pump can reach the necessary temperatures anyway, it shouldn't take that much to have it heat your hot water as well, which generally should roughly halve the electricity you need for that.Also mind you that most heat pumps are modulating, so even a nominal 9 kW compressor will not run anywhere near that most of the time. My own air/water heat pump is a nominal 4 kW model, but it only pulls ~ 3kW while heating up hot water, otherwise, it runs at ~ 300 to 500 W down to ~ 0 °C outdoor temperature with a few minutes of ~ 1.5 kW after startup. So chances are you'd only have to deactivate the water heater when it's extremely cold outside to stay under the limit. On the other hand, if you plan with resistive backup heat, you have to consider that power in addition to the "normal load".As you mentioned that you required relatively high water temperature for your radiators: What is your water throughput and temperature spread with the current setup? Heat pumps are generally most efficient with the lowest-possible water temperatures, and as a consequence of that are generally designed to run at high throughput and thus low temperature spreads. So, if the currently required high source temperature is just a result of a low-throughput pump, you might be able to improve things there. But if the pipes are too small, that also can get you a noise problem, of course.Also, beware of storage tanks and the like with heat pumps. While there might be uses for them, they are also often used by contractors to hide bad planning and end up reducing efficiency. Especially, they tend to be used to hide a mismatch between an oversized heat pump and the house where the mismatch would cause the heat pump to cycle rapidly, and the storage tank is used to absorb more heat faster and then slowly release it to the house. But that necessarily means that the heat pump runs at higher temperatures than necessary, and that is bad for COP. Ideally, you want your heat pump to be running 24/7 at the minimum output power that is required to keep your house warm.In the same vein, beware of oversized heat pumps in general. Contractors tend to recommend oversized heat pumps because they want to be sure the customer won't complain about lack of warmth. And also because of incompetence (because oversizing largely didn't hurt with fossil heating systems and that's all they really know). There is a limit to how far a heat pump can modulate down (around 50%, varies by model, obviously), plus it might be a bit less efficient at the very low end, and if you are using a heat pump that's nominally oversized by a factor of 2, you will effectively not be modulating at all because the minimum power is sufficient for the coldest days.As for your house being split between floor heating and radiators: I have no idea whether there are any off-the-shelf solutions for this, but maybe it is possible to run the heating in some sort of interleaved mode? Like, split this into two independent loops, and then heat them alternatingly, one at ~ 30 °C and the other at ~ 55 °C? Or just use two separate heat pumps? I mean, I have no idea whether any of that makes economic sense, but it really would be unfortunate to not use the potential of the combination of a heat pump and the low temperature required by under floor heating.Ah, yeah, and beware of FUD. There is a lot of FUD around heat pumps, even ITT. While over-optimistic calculations are a thing and bad installs by inexperienced installers seem to be somewhat common, much of the horror stories you hear are told by people who obviously have no first-hand experience and are just parotting something they heard somewhere without any understanding of the respective context, but they still are absolutely certain that the only reason why some heating system doesn't perform as expected must be because of the heat pump that happens to be involved.One pitfall in particular when comparing COP numbers you see people report is that hot water potentially has a huge effect on COP. If you are in a well-insulated house with under-floor heating and with many people who take a bath every day, you can easily end up with, say, 4000 kWh of hot water produced at ~ COP 2 (thus 2000 kWh electricity) and ~ 8000 kWh of heating produced at ~ COP 4 (thus also 2000 kWh electricity) with a total (S)COP of 3. Same house, fewer people, less bathing, and you might be much closer to (S)COP 4.Also, if you can read German, the haustechnikdialog forum can be an invaluable resource as to experiences, DIY solutions, hacks, optimization, common planning mistakes and the like:https://www.haustechnikdialog.de/Forum/

author: zilp
author_rank: Frequent Contributor
timestamp: February 18, 2024, 03:20:29 pm
content: Quote from: Siwastaja on February 18, 2024, 01:26:46 pmAlso, glycol has a lower heat capacity, so you need more throughput to achieve the same heating power, i.e., larger diameter pipes or higher power pump, potentially larger heat exchangers, ...

author: coppice
author_rank: Super Contributor
timestamp: February 18, 2024, 03:29:27 pm
content: Quote from: Siwastaja on February 18, 2024, 01:26:46 pmSo, when the inevitable bad things do happen, like a power fault that takes time to fix, how to you get a system like this back up, and is it likely to have burst the plumbing somewhere?To avoid regulatory issues with leaks between the water circuits, do you have to ensure your heat pump circuit meets hygiene standards? Most regulations don't seem to like relying on the hygiene of a circuit that is rarely touched, and refreshed.

author: coppice
author_rank: Super Contributor
timestamp: February 18, 2024, 03:30:26 pm
content: Quote from: zilp on February 18, 2024, 03:20:29 pmThe same is true everywhere we use water glycol. We usually live with that for the benefits it brings.

author: Marco
author_rank: Super Contributor
timestamp: February 18, 2024, 03:44:31 pm
content: I thinkthe creator of the Heatbooster's storyis instructive. He had a pretty shitty insulated house, so he just put an absurd amount of PC fans on his radiators and got a relatively big (12 kW) air source heatpump and two heatpump boilers (for hot water, I assume his family likes rain showers). Due to the peculiarities of the Dutch subsidy system you can get individual rebates for each heatpump, so the heatpumps themselves cost you bugger all (ignoring taxes, which you are paying any way).The better heatpumps have heating output specifications for lower temperatures ... at minus ten external and 40 degree water temp lets say 3/4th, it doesn't go down that fast (COP does, but heating capacity holds up pretty well).For monoblocks, anti-freeze valves are popular. They just empty the system if the water in the pipes start freezing.PS. his home was shitty insulated by modern standards, not 1900's wooden home single glazed bad ... but he had double brick walls without blown in insulation, so pretty shitty nonetheless.

author: zilp
author_rank: Frequent Contributor
timestamp: February 18, 2024, 03:51:50 pm
content: Quote from: coppice on February 18, 2024, 03:29:27 pmYou drain the water before it gets to that, and you fill it back up afterwards.Also, in western Europe, that generally just doesn't happen. The grid is generally sufficiently redundant that you won't be without electricity for any significant amount of time. And fo the very rare exceptions, well, see above.

author: ejeffrey
author_rank: Super Contributor
timestamp: February 18, 2024, 05:28:19 pm
content: Even with defrosting an air source heat pump should keep its COP moderately high.To create ice, you have to have absorbed a ton of latent heat (to condense the vapor and then freeze it) and only need to return a small fraction of that heat to melt the ice. If your heat pump is correctly detecting ice then it's basically not a problem. If your heat pump is "defrosting" frequently even when there is no ice buildup that's going to cost you COP for sure, but that's just a defective system not a problem with heat pumps in general.

author: zilp
author_rank: Frequent Contributor
timestamp: February 18, 2024, 05:51:59 pm
content: Quote from: ejeffrey on February 18, 2024, 05:28:19 pmAlso, to spell it out explicitly: Many heat pumps use their own heat for defrosting. Either they use heat from a hot water storage tank (not ideal, but still roughly twice as efficient as resistive heating) or they even extract heat from the under-floor heating system. Some also use resistive heat for defrosting, which isn't that great and can indeed reduce your COP for the day quite a bit.

author: Zero999
author_rank: Super Contributor
timestamp: February 18, 2024, 06:48:18 pm
content: Quote from: Siwastaja on February 18, 2024, 01:26:46 pmI don't see how poisoning is an issue. Antifreeze contains denatonium, which has a nasty bitter taste. If the water became contaminated, then it would taste too bad to drink enough to be poisoned.

author: nctnico
author_rank: Super Contributor
timestamp: February 18, 2024, 07:40:10 pm
content: Quote from: Zero999 on February 18, 2024, 06:48:18 pmTry to tell that to kids who just made lemonade or so.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 18, 2024, 08:16:56 pm
content: Quote from: zilp on February 18, 2024, 03:11:40 pmI assume that when someone sees k or K before W they will know it means kilo, same as in KB for kilo bytes and Kb for kilo bit, where there is an actual difference for the b. I'm not sure where I picked it up but have always used upper case letters in (digital) technology when shorting Kilo, Mega or Giga.But that aside. I might be wrong in using the hour when expressing energy usage, but to clarify on a very cold day the system uses on average 31,5MJoule (8.75KWh) every hour, so 756MJoule (210KWh) per day. But this is only when it is -4degree Celsius or less outside. This is an average based on usage over the years.Per heating season our system uses on average 58781845200Joule (16328,3KWh) to keep the house warm. The season is about 6 months. This number is based on how many times I have to heat up the storage tank in a season and the average amount used form the tank.This includes the losses from the tank of course, which is maybe 0.5 to 1 degree per hour when the tank is at its top temperature, and drops down when the temperature in the tank goes down.Quote from: zilp on February 18, 2024, 03:11:40 pmThe water heater has is a resistive immersion heater type rated 2KWh, which means it draws ~8.4A when on. Not sure about the ratings of the refrigerator and the freezer, but it all adds up. The water heater is on a clock and only heats during the night. We won't bother with trying to reduce the energy bill on that, because our warm water consumption is not that high.It might be FUD, but we heard stories about the "Linky" cutting you of directly when the current goes over the set limit. No idea if it is true and it might never happen when the heat pump is running. I just want to be sure it won't.Quote from: zilp on February 18, 2024, 03:11:40 pmCould be an option but would require sensing that the water heater is on.Quote from: zilp on February 18, 2024, 03:11:40 pmThe remainder of your post is very educational and I will certainly look into adaptations to my system. At the moment the regulation for the room temperatures is based on a set temperature and a hysteresis between the measurement. The rooms with the radiators start heating when the temperature on the sensor drops half a degree Celsius below the set point and stops when the set point is reached. Depending on the water temperature there is an overshoot, but that is fine for us. For the rooms with the underfloor heating it is 0.1 degree Celsius. The response is much slower but will also give overshoots. On every valve in the system there is an on/offthermo electric actuatorthat is controlled by the Raspberry PI. Maybe I can change it to run more constantly and regulate the temperatures. Need access to the heat pump system for that though, and that needs aid from the installer and technical data on protocol and interface.

author: Bud
author_rank: Super Contributor
timestamp: February 18, 2024, 08:49:05 pm
content: Not sure why is the conversation... According to EU dickheads you should be buying T-shirts and sunglasses, rather than worry about heat pumps.

author: nctnico
author_rank: Super Contributor
timestamp: February 18, 2024, 08:59:29 pm
content: Quote from: zilp on February 18, 2024, 03:11:40 pmThere is an off-the-shelve solution for that. It is a simple mixer unit with it's own pump that takes in hot water from the hot water source and mixes that with the cold water coming from the tubes that make the underfloor heating system. These have been in use for decades.For my underfloor heating installation I have made a boiler simulator which uses a regular Honeywell digital thermostat which tells the simulated boiler what the water temperature should be. All the room temperature control loop intelligence is in the thermostat. The boiler simulator opens the hot water supply until the mixer unit reaches the setpoint temperature.

author: zilp
author_rank: Frequent Contributor
timestamp: February 18, 2024, 09:55:11 pm
content: Quote from: nctnico on February 18, 2024, 08:59:29 pmThat doesn't solve the problem. The problem isn't that the water is too hot for the under floor heating, the problem is that the high temperature is inefficient to generate with a heat pump, and it's kinda bad to have your heat pump generate 55 °C at great expense and then cool it back down to 30 °C.

author: Marco
author_rank: Super Contributor
timestamp: February 18, 2024, 10:07:10 pm
content: Google tells me the linky limits current assuming a reference voltage of 200V, so it's going to be closer to 10kW in reality.PS. is that really still in there in France? The Dutch smart meter regulations removed that pretty much immediately (or rather it's forbidden by government regulations for them to have contactors now). Moving from the sealed main breakers with large safety margin to a hard switch off probably caused way too much problems.

author: nctnico
author_rank: Super Contributor
timestamp: February 18, 2024, 10:50:57 pm
content: Quote from: zilp on February 18, 2024, 09:55:11 pmIf the heat pump is optimised for higher temperatures it might not be a problem. Mixing to a lower temperature doesn't matter as no energy gets lost. Still, if it where up to me I'd change to underfloor heating in the entire house.

author: Marco
author_rank: Super Contributor
timestamp: February 18, 2024, 11:02:10 pm
content: It's a shame it's getting a bit late in the year to see how far you can get with some DIY modding of the radiators with PC fans and some thermally controlled activation like Heatbooster.Proper fan coil units aren't that expensive either and will give you a guaranteed heating output so you can just do the math. You could gamble on the DIY solution and replace the radiators with fan coil units if it doesn't work out.

author: zilp
author_rank: Frequent Contributor
timestamp: February 18, 2024, 11:14:39 pm
content: Quote from: pcprogrammer on February 18, 2024, 08:16:56 pmI mean, I guessed as much, but thats not exactly a reason to write it wrong, is it?Quote from: pcprogrammer on February 18, 2024, 08:16:56 pmThat was somewhat of a convention to differentiate the base 2 prefix (K for 1024) from the base 10 SI prefix (k for 1000) when specifying memory or storage sizes because they tend to be in powers of two. But for one I doubt that you are calculating in 1024 Wh units, and also, that convention has been kinda deprecated in favor of the IEC binary prefixes (Ki/Mi/Gi/Ti/...), so the unambiguous way to write that would be KiWh.Quote from: pcprogrammer on February 18, 2024, 08:16:56 pmNo, it would be correct for expressing energy usage. Because it is a unit of energy. But it is wrong (and confusing) when expressing power. This is the same as specifying speed in kilometers.Quote from: pcprogrammer on February 18, 2024, 08:16:56 pmI.e., 8.75 kW times 1 hour per 1 hour = 8.75 kW * 1 h / 1h = 8.75 kW. I mean, "8.75 kWh per hour" is also fine, but if you specify just an amount of energy, it is unclear what time span that is for, and especially when you then say something like "the day average is", as that suggests that the time span might be a day.Quote from: pcprogrammer on February 18, 2024, 08:16:56 pmYeah, that makes sense. And indeed not that bad for 240 m².Quote from: pcprogrammer on February 18, 2024, 08:16:56 pmYeah, I was more thinking of the defrost horror stories and heat pumps supposedly not lasting long and all that. No clue about your smart meter thingy. But you can reactivate the supply, can't you? I mean, if that requires a visit from a technician or something, that would be bad, but otherwise, I guess it might just not be a big problem.Quote from: pcprogrammer on February 18, 2024, 08:16:56 pmYeah, that's a thing you can buy. But whether that makes economic sense is something that you'll have to figure out, of course.Quote from: pcprogrammer on February 18, 2024, 08:16:56 pmI guess that's usually not really officially documented, but you can find the results of people reverse engineering protocols of various models on the internet.But, yeah, ideally you calibrate the flow of all heating loops in the house such that you don't need any per-room control. Obviously, that is not possible if you need to vary temperatures, but you can try to get as close as possible. You want to have the largest heating surface possible at all times with the largest possible flow to minimize the source temperature that you need to feed the required heating power into the house.

author: tszaboo
author_rank: Super Contributor
timestamp: February 18, 2024, 11:18:25 pm
content: I talked with a college, who had geothermal at his new built. It needs to be on constantly, since it would take days to heat up the house from ie. 10 degrees. For high efficiency, you need underfloor heating. So that means you pretty much have to rebuild your entire house, since the floor has to go everywhere, then painting then the work never stops. I estimated 10K for geothermal system, and 30-40K for renovations. The garden will go as well if they dig. Basically you are building a new house. Plus as we know this work lasts months, your house is unlivable in the meantime, people promise deadlines and no show, the usual renovations stuff.I didn't give up on heatpump heating, but I'm only interested in air sourced, basically airco with reverse operation. As an addition to the district heating.Quote from: Bud on February 18, 2024, 08:49:05 pmYeah, these politicians simultaneously force you to buy an electric car, and renovate your house with these very expensive systems. I really don't know why they cannot do back of the napkin calculations, to see that they should be working on P2G plants for sustainable energy. That way we don't have to replace the entire infrastructure of basically everything we own. But yes, let's just make simultaneously obsolete our cars and our houses, and this damn inflation.

author: Marco
author_rank: Super Contributor
timestamp: February 18, 2024, 11:31:13 pm
content: Quote from: tszaboo on February 18, 2024, 11:18:25 pmHis house is almost certainly superinsulated to be able to work like that, with his control loop superconservative. No way the system has that little surplus power, it just refuses to use it because of the controller. He probably needs to raise the heating curve ("stooklijn" in Dutch, dunno the exact English term) to heat up fast.

author: zilp
author_rank: Frequent Contributor
timestamp: February 18, 2024, 11:35:48 pm
content: Quote from: tszaboo on February 18, 2024, 11:18:25 pmWhy would that be better than a full calculation that might suggest that P2G at 70% efficiency with burning the result at 95% efficiency might not actually be cheaper than running a heat pump at 400% efficiency, as it increases the demand for electricity by 500%?

author: baldurn
author_rank: Regular Contributor
timestamp: February 18, 2024, 11:54:30 pm
content: Quote from: nctnico on February 18, 2024, 10:50:57 pmBy Carnot's theoremhttps://en.wikipedia.org/wiki/Carnot%27s_theorem_(thermodynamics) we know that it is always less efficient to make hotter water. Real heat pumps are even worse than the theoretical Carnot limit. You therefore absolutely do not want to make 55 degree hot water and mix it down to 30 degrees. That might halve the COP or worse.My Panasonic air to water heat pump has a function that can make water for two circuits plus a separate loop for hot tap water (so three circuits/loops in total). It is just a simple remote controlled valve. The heat pump sends a signal when it wants the valve to switch circuit. Simple as that.

author: nctnico
author_rank: Super Contributor
timestamp: February 18, 2024, 11:54:51 pm
content: Quote from: tszaboo on February 18, 2024, 11:18:25 pmThat is not necessary. You can retrofit underfloor heating in cement floors as the finishing layer is soft by design. In my case I used a mill to make slots in the floor where the underfloor tubing went into.

author: Marco
author_rank: Super Contributor
timestamp: February 19, 2024, 12:03:16 am
content: The insolation mats with ready made grooves for piping only raise the floor by a couple cm too, it's more the sheer amount of labour and mess involved.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 19, 2024, 07:17:01 am
content: Quote from: Marco on February 18, 2024, 10:07:10 pmGood to know.I have not looked into regulations around this. The linky for us is fairly recent and when the time came they wanted to install them there came the horror stories about radiation causing cancer, cutting you of when over powering, etc. Did not bothered about that because a: I don't buy into the radiation bullshit and b: our energy consumption has always been low enough to have no "fear" about a cutoff.But with a heat pump the possibility arises that the consumption goes over.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 19, 2024, 07:33:07 am
content: Quote from: nctnico on February 18, 2024, 08:59:29 pmI'm usingrobot distributorsfor the underfloor heating.If there is an option to connect to the heat pump and control the output temperature with my own system I can scrap the mixing valve that is in there now. This most likely improves the performance.The 55 degree Celsius water temperature is not a must. It depends on how many zones are on at the time. The radiators work fine with 40 to 45 degree Celsius, but when the whole house is demanding heat the input temperature needs to go up to maintain the needed 40-45 degrees on the radiators. But even with lower temperatures on the radiators they manage to keep a minimum temperature in the rooms with extreme cold outside.For the bedrooms it is not an issue if they go down to 14 degrees or less, as long as they stay above freezing temperature.At the moment they are set to 15 and 15.5.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 19, 2024, 07:34:07 am
content: Quote from: Marco on February 18, 2024, 11:02:10 pmNot going to happen. Fans make noise.

author: m k
author_rank: Super Contributor
timestamp: February 19, 2024, 09:15:15 am
content: That cooling thing of mine was a bit one sided.What I think is a heat pump is a circulation where material is changing its phase.So monoblock has a heat pump inside of it and heated water is something else.So cooling with a water heating radiator is just cooling with a radiator.Here cooling with air or ground to water system is many times out since the system is also generating the base of warm clean water.But system for water heating only can be used for cooling, just turn the process around and bypass the reservoir, if needed.There moisture must be taken seriously, even here, or actually especially here.If memory serves a human is exhaling 1/5 litres of extra water per day.So even without cooling humans are actively increasing moisture.No idea how cold a radiator can be in those cases, but finally wall behind that radiator can probably be close to dripping.Usually intersection of wall and floor has some kind of a skirting, behind it is a good place for a secret habitat.We have a machine ventilation with heat conservation.There is also a possibility to bypass that conservation.But when that bypassing is actually beneficial, only when outside is cooler than too warm inside.Here it's nights off and days on, more than a bit tiresome if the operation is manual.The house here is 150-160m2, two floors and sloped base.Last year's total electricity bought was 10MWh, Jul-Aug was 1MWh.Parts of the place had more dropped temps and few m3 of logs were burned.(dropped temps are not nice, I know, just an issue of rig)Estimated total energy for 23C room temperature and four persons is around 25MWh, warm water is few MWh.Costs are also important.It becomes less stupid to not add a gear when cost is stupid.My opinion is that some of regulated costs are stupidly high, and artificially.BTW,I forgot the shed.With few bigger power tools the estimated 15A surplus is used in no time.Mowing can be done with 10A, but leg work increases.Branch shredding also, up to a point, there time is the issue.Here renting a machine is practically not available, everybody must have their own, so market is limited.

author: zilp
author_rank: Frequent Contributor
timestamp: February 19, 2024, 09:56:14 am
content: Quote from: pcprogrammer on February 19, 2024, 07:33:07 amThis means that with a stronger pump, you could lower the temperature. Of course, with a stronger pump, there is a risk of noise if many loops are closed (and thus the flow speed in the remaining loops increases). To prevent that (if it is a problem at all, which you really only can figure out by testing), you need to either plan without individual room control (i.e. (almost) all loops open all the time, calibrated to provide the required heating power, that's how I run my own system), or you need a pump that regulates the output pressure, or you need a bypass valve that limits the pressure by short-circuiting a part of the flow.

author: tszaboo
author_rank: Super Contributor
timestamp: February 19, 2024, 10:48:44 am
content: Quote from: Marco on February 18, 2024, 11:31:13 pmIt's designed to be a very efficient system, with the water temperature barely above the setpoint. The higher the temperature difference, the lower the efficiency of a heatpump. You can find some data here:https://en.wikipedia.org/wiki/Heat_pump#Performance, but keep in mind these are going to be the cutting edge numbers that are not really afforable.Quote from: nctnico on February 18, 2024, 11:54:51 pmMy neighbor did that to get rid of the radiators in his living room. It was months of works, lot of dusts, so much that the rest of the house was unlivable. It's not just cutting some slots. It's removing all furniture, the floor, isolation, cutting plastering, waiting for it to dry, a new floor, and then the rest that you need to do.Quote from: zilp on February 18, 2024, 11:35:48 pmBecause heat pump actually doesn't solve the problem. The problem is that we need energy to heat our homes during the winter. And it doesn't matter where it comes from. My house heating comes from a waste energy of a power plant, how much is the efficiency of that? but anyway back to the topic.You might compare 70% and 500% and say 500% is better. But 70% is during the summer, and 500% is during the winter. If the energy for that 70% conversion is provided by free (as in beers) solar energy, your efficiency doesn't matter one bit.If we all install solar panels, the upfront cost is 5-10K per house, depending on how big your roof and ambitions are. And it's getting cheaper. And we already see that it can cover 100% of our usage during certain days the summer. In these days electricity is cheap, sometimes even free.You take this electricity, run it through P2G and make gas out it, that you burn during the winter. Gas storage is a solved issue, unlike seasonal electricity storage. Plus you use CO2 in the process, that you can capture for free at power plants, during the winter. In fact the price of CO2 could be negative, since the power plant doesn't have to pay the carbon tax if it captures the CO2. There just isn't an large industrial process that uses that much CO2 as we make now.This is just the most sensible way of handling the issue for the next decades.

author: nfmax
author_rank: Super Contributor
timestamp: February 19, 2024, 10:51:45 am
content: Quote from: zilp on February 19, 2024, 09:56:14 amRather than restricting flow, it might be possible to turn on radiator fans only when extra heat input is needed, and turn off during 'setback' times. The heat pump weather compensation should react appropriately, modulating the compressor to keep the circulating water temperature at its target value. There is then no need to restrict the flow in the hydronic circuit.Just my thoughts

author: tom66
author_rank: Super Contributor
timestamp: February 19, 2024, 11:05:56 am
content: I'm quite a fan of 'eco technologies' but I am a little skeptical about heat pumps for now for the average British home. For a new build house, built from scratch with excellent insulation, large pipes, and underfloor heating and/or large radiators they might make sense. We have a 1930s detached house. It has loft and cavity wall insulation, and double glazing, but that's about all in terms of efficiency improvements. It has plenty of thermal bridging and uninsulated ground floor (project for this year is to insulate that). In the depths of winter the boiler is running with flow temperatures of 65C+ to warm up rooms. Instead of a heat pump I've taken the cheaper approach of zoning the thermal load so that rooms we don't use as much don't get as much heating (and doors are closed to limit rate of heat movement). The OpenTherm controller means that the temperature of the boiler is kept closely in line with the demand signal from the wireless TRVs, so the boiler hopefully runs as efficiently as it can.I probably will look at a heat pump in the next 5-10 years and seeing the outcome from people who had them fitted today. But knowing my luck that will mean all the grant schemes have gone away by then. I know a utility company here will install one in my house for about £3,000, but that's on top of a £7,500 grant from the government. The COP would need to be >3.5 to make it cost effective compared to gas.Perhaps I'm just a luddite though and will look back on this post in 5 years wondering what I was so concerned about.

author: Miyuki
author_rank: Frequent Contributor
timestamp: February 19, 2024, 11:22:54 am
content: Quote from: zilp on February 19, 2024, 09:56:14 amConstant pressure pumps have been here for decades and all efficient ones with permanent magnet motors can do it. There is no reason to use old-style single-phase induction motors.Another possibility is to change some radiators to bigger or use fan coils. Plain steel radiators cost close to nothing if you do not need some fancy design ones.The main issue is that many heat pump installation companies are pure scammers and know nothing about it. They choose the wrong overpriced models, and cannot set the heating system right (flow, balance, and so on)Right-chosen heat pump, even when Air-Water shall not activate resistive heating except on record cold days.Last year I bought a new fancy wood boiler with lambda control, it is a great thing, can burn anything, big pieces, small pieces, scraps, and dust. From the chimney goes nothing except some condensation when is freezing. With storage tank. It is very convenient.I also have an Air-Air AC/Heat pump, as it got pretty hot here last years it is handy to have temperature control both ways. And for heating, it has a higher COP than the Air-Water system can reach.I'm planning to small Air-Water system for days when there is a lot of sun, but for cold days without sun, wood is the right choice for me. And pellets are crazy expensive here nowadays.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 19, 2024, 12:05:44 pm
content: Quote from: zilp on February 19, 2024, 09:56:14 amIt will boil down to experimenting with it all.There is also the option of opening all the zones and use the adjustable return valves to control the flow. Have the system regulate the temperature output of the heat pump to maintain a livable temperature in the rooms. Incorporate the outside temperature in the equation and see what it does.Another option is the use of a controllable variable speed circulation pump. When only a few zones are open reduce the flow with the pump.

author: tom66
author_rank: Super Contributor
timestamp: February 19, 2024, 12:26:04 pm
content: Seems that most heat pump engineers suggest that over-zoning causes problems. You want the heat pump to be providing constant heat to all rooms, with some exceptions for times when you are out of the home for instance. So my little trick of not heating rooms (via home automation) when unoccupied, and zoning rooms to different temperatures, would be not recommended. This is because the heat pump will need to work very hard to get that room up to temperature after returning home or to change temperatures according to the schedule, which means the COP will fall dramatically for the whole house during those periods.The general principle of low temperature design is to have the system running more or less continuously keeping the radiators 'ticking over', whereas typical gas/oil boiler CH systems rely on cycling the boiler. In the boiler case, you oversize the boiler slightly so that even if it is -10C outside and +10C inside the home can get up to +20C within about an hour. A heat pump would probably struggle with that.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 19, 2024, 12:47:22 pm
content: Quote from: tom66 on February 19, 2024, 12:26:04 pmThat is what I'm finding more and more, that it is better to let it run continuously at lower temperature. I will have to discuss this with the companies we invited for the quotes.With underfloor heating it is in it's nature to be very slow. We have been away several times over the years near the end of the season to return to a cold home. About 12C inside and it would take the whole day to get the rooms with the underfloor heating back up to temperature. On the one hand the wood burner setup that takes several hours to heat up the first tank to >40C and on the other hand the slow process of the underfloor heating.It would be nice to return to a home at set temperatures after a 10 hour drive from the Netherlands.

author: nfmax
author_rank: Super Contributor
timestamp: February 19, 2024, 01:31:36 pm
content: Quote from: pcprogrammer on February 19, 2024, 12:47:22 pmWhat you need in that case is remote control - probably via the Internet in this day & age.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 19, 2024, 01:47:58 pm
content: Quote from: nfmax on February 19, 2024, 01:31:36 pmWon't be necessary when the system keeps on running when we are not there, and with the old system it would not help either because the wood burner can't start it self and the storage tank won't be full.It is the whole point of the discussion that a heat pump system needs to run constantly to maintain its performance ratio's.

author: zilp
author_rank: Frequent Contributor
timestamp: February 19, 2024, 03:47:39 pm
content: Quote from: pcprogrammer on February 19, 2024, 01:47:58 pmIf you are away for multiple days, it shouldn't hurt to let the temperature drop (and probably save energy overall), you'd just have to have it start heating back up a day or so before you return. But varying temperatures throughout the day probably/usually isn't a good idea (in that it either just doesn't work, or you'd have to increase temperatures so much that you get a bad COP, and you'd have to oversize the heat pump, which is also expensive and decreases the COP).

author: zilp
author_rank: Frequent Contributor
timestamp: February 19, 2024, 04:05:58 pm
content: Quote from: pcprogrammer on February 19, 2024, 12:05:44 pmYep, that is the ideal way to do it where you don't need to regularly change room temperatures.Quote from: pcprogrammer on February 19, 2024, 12:05:44 pmWell, that is sort-of what your regular heat pump will do by default. Specifically, it will set the source temperature target based on the outdoor temperature and will then adjust the compressor speed to hold that temperature, and if the temperature rises some hysteresis above the target (i.e., when the minimum compressor power is too much), switch off the compressor and let the temperature drop. And for controlling the temperature inside, you then can have either individual per-room controllers that asjust the flow per room, and/or a room thermostat that influences tha target source temperature/causes the compressort to be shut off when the target room temperature is reached.Quote from: pcprogrammer on February 19, 2024, 12:05:44 pmWell, yeah, that's essentially what a constant-pressure pump does.However, you also have to be careful that you don't go under the minimum flow required by the heat pump, which tends to be relatively high, as you are otherwise likely to get rapid cycling of the compressor, which is neither good for the compressor nor for the COP.

author: tszaboo
author_rank: Super Contributor
timestamp: February 19, 2024, 04:07:51 pm
content: Quote from: zilp on February 19, 2024, 03:47:39 pmyou would think that in this century there would be an easy way to control the temperature.I had to deal with a Dutch temperature controller for gas heating. It had settings for only two temperatures, one for heating, and one for "set back temperature". So I tried placing the setback during the day, when I'm at work. It was impossible. The setback temperature was hardcoded to be at the end of the day, because you are surely not going to heat during the night, and it's impossible that someone else will have a different schedule or requirement for heating.Now I have a google Nest thermostat, where you can set the temperature, but the measurements on it are just plain off. Because they put the temperature sensor next to the Wifi, and it heats up. And the wall behind it heats it up, where all the heating system stuff is. You would think that this would be an issue that they resolved during development of the product, but no. Ah but you see, it's possible to connect an external temperature sensor to the thermostat, and use the value from that. If you live in North America, not possible in Europe.

author: Marco
author_rank: Super Contributor
timestamp: February 19, 2024, 05:06:30 pm
content: Quote from: tszaboo on February 19, 2024, 10:48:44 amI know, that's why I said it's the control system. It needs headroom power, because the thermal loss of the house obviously isn't static ... if it took days to heat up the house to setpoint at 0 degrees ambient due to lack of power, it wouldn't be able to get to set point at all at minus 10 ambient. That's almost certainly not the case, the control loop is the limiting factor in letting it respond faster. It values efficiency over response time, but you can probably hack it if you have different priorities.

author: Marco
author_rank: Super Contributor
timestamp: February 19, 2024, 05:15:04 pm
content: Quote from: tom66 on February 19, 2024, 12:26:04 pmThey are biased towards modern homes. Those homes might drop only a degree overnight with heating off ... so yeah, easiest to just keep everything equilibrium.For me it's more like a degree every 30 minutes, the potential gains from lowering temperature during the night and working hours are far different.

author: Marco
author_rank: Super Contributor
timestamp: February 19, 2024, 05:43:15 pm
content: Quote from: pcprogrammer on February 19, 2024, 07:34:07 amBelow 800 rpms it's pretty much inaudible.

author: zilp
author_rank: Frequent Contributor
timestamp: February 19, 2024, 05:51:13 pm
content: Quote from: tszaboo on February 19, 2024, 10:48:44 amExcept ... it does?! I mean, I don't really understand what you are trying to say here, but I would think the whole reason for switching to renewables is that it does matter where our enery comes from?!Quote from: tszaboo on February 19, 2024, 10:48:44 amThere is no efficiency for that. But there is an efficiency for that power plant as a whole. And if you feed that power plant with methane from P2G, you get an efficiency that you can compare to directly using renewable electricity. And it's going to be atrocious.Quote from: tszaboo on February 19, 2024, 10:48:44 amWhile you are right that I simplified quite a bit, your conclusion doesn't exactly follow.Quote from: tszaboo on February 19, 2024, 10:48:44 amOK ... and what is going to be the price of a kWh of methane from a P2G plant that sits idle 95% of the year in order to produce methane from free electricity the few hundred hours a year that that is available?And mind you, if a kWh of electricity can make 4 kWh of heat in a heat pump, while your P2G plant needs 6 kWh of electricity to create 4 kWh of heat in a gas heating system, even if your P2G plant somehow magically was free, that gas is more expensive as soon as the electricity used by the P2G plant is more than a sixth of the average market price. So, "cheap" electricity really doesn't cut it, it has to be almost free for this to be economical, especially when considering that the plant probably isn't actually free in reality.Either you have a plant that's idle most of the time, which is going to make the gas expensive, or you increase the load, which requires feeding increasingly expensive electricity into it, which is going to make the gas expensive, too.Plus, there are limits to how much renewable electricity we can generate here. Like, people here in Germany use roughly 500 TWh of heat for heating homes per year. That's roughly 2.5 times the amount of renewable electricity generated last year. So, to feed those P2G plants for that purpose alone, we would have to install ~ 3.5 times what we already have in solar and wind. And then, the demands for transportation and industry comes on top.Maybe, just maybe, it makes more sense to install 125 TWh of solar and wind and then use heat pumps to turn that into 500 TWh of heat?Quote from: tszaboo on February 19, 2024, 10:48:44 amWell, true, but also misleading.For one, we don't need seasonal electricity storage. The wind doesn't stop blowing in the winter. Actually, you generally have more wind during winter than during summer. And also, funny enough, wind correlates with heating demand, because wind cools houses.Then, there is a type of renewable energy source that doesn't depend on direct sun or wind that can be used to provide energy when both of those are in short supply. It's called a heat pump. It can be -10 °C, no wind, no sun outside, and my heat pump still manages to move multiple kW of renewable energy from the outside into my home, using relatively minor amounts of electricity for the purpose. I mean ... how about we use that rather than trying to generate tons of electricity that we then don't really know how to store, other than using rather inefficient methods?And what is great about heat pumps is that they can run both with renewable electricity, but also with electricity from gas power plants, say. And that's where electrolysis and P2G come in: If you run a P2G plant 24/7, the capital costs per kWh aren't that high, so you can slowly fill gas storage all year. And the releatively little time per year when both sun and wind are lacking, you can then burn that gas in peaker plants (which also are relatively cheap to build) to fill the gaps. So, you have your heat pump running most of the time at ~ 400% efficiency, and only a few days a year, you feed it with electricity from P2G methane at a total efficiency of, let's say, 100% (those usually will be colder days, so probably not peak COP). This way, the inefficiency of the conversion process doesn't really matter all that much.Oh, and those P2G plants then also can contribute to grid stability by shutting down production when needed. Because one alternative to storage is to have variable loads. With those, you can add generation capacity that doesn't just sit idle most of the time (which would be a waste of capital), which then still is available to keep vital things running in critical situations by shutting down some variable loads as needed.Quote from: tszaboo on February 19, 2024, 10:48:44 amExcept there won't be any power plants to provide CO2.Mind you that we can't emit any more CO2, so burning fossil fuels, capturing the CO2, using that for P2G, and then burning that P2G gas and releasing the CO2 into the atmosphere afterwards is not a solution, as the CO2 would still end up in the atmosphere, and CO2 emissions would only be halved at best (because the carbon would essentially be used twice before being released).So, the only way to implement this without CO2 emissions would be to implement a closed loop. But mind you that that then would mean that you would have to burn the gas as you are generating it in order to get the CO2 back to feed into the P2G plant. Which is obviously economical nonsense, are you are then trying to feed electricity back into the grid that you just bought it from, with additional costs and energy losses from your conversion processes. Well, or you could try storing the CO2 for half a year or something ... which would double the amount of gas storage you need. Or something.Also, systems for capturing CO2 aren't free either.Quote from: tszaboo on February 19, 2024, 10:48:44 amIf you ask me, that sounds more like a more uninformed way of handling things.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 19, 2024, 05:59:06 pm
content: Quote from: zilp on February 19, 2024, 04:05:58 pmThe way it is now the rooms are basically always on the same temperature setting. The only exception is my upstairs hobby space, where I will raise the temperature in case of prolonged stay in the room. It has 4 big radiators and heats up quick even with low water temperature. When I'm up there just to solder some wires or change some components on an experiment, I just leave the temperature as is on 16.5 degrees Celsius on the sensor.I will have to experiment when the heat pump is installed to see what works best.Quote from: zilp on February 19, 2024, 04:05:58 pmThe guy who gave the quote for the De Dietrich heat pump explained that the idea was to set the heat pump controlled by outside temperature at, for example, 35C output water when >10C outside and 55C when <-10C outside. Also something to experiment with.

author: zilp
author_rank: Frequent Contributor
timestamp: February 19, 2024, 07:28:00 pm
content: Quote from: pcprogrammer on February 19, 2024, 05:59:06 pmWell, yes, that is something to experiment with, but heat pumps are optimized for particular temperature ranges, so you probably should try to find out the minimum temperature that you need to keep the house warm before selecting the heat pump. 55°C is at the high end of what "regular" heat pumps can provide, and rather inefficiently so, so, if you really need 55°C, you might need a high temperature model. However, if you can reliably keep the house warm at 40°C, a "regular" model might do the job just fine.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 19, 2024, 07:54:22 pm
content: Quote from: zilp on February 18, 2024, 09:55:11 pmYes, shunting down to lower temperature distribution makes the whole system have the worse COP of the higher temperature. For small differences, maybe 10degC worst case, between the two distributions, it's not a big deal, but for anything bigger, it is. The (somewhat complex) solution is to use two separate (large enough, say at least 100-200 liters) reservoir tanks and a valve which redirects the heatpump to alternatively heat one of the tanks to different temperature than the other; e.g., for half an hour heat tank 1 with setpoint of +30degC, then for half an hour turn the valve to redirect water to go to tank 2 with setpoint of +40degC.This is what the usual air-to-water installation would do anyway, alternating between the heating circuit water and domestic hot water, latter being almost always significantly hotter (and thus lower COP, but still more than 1). In this case you would just have a third storage tank.Another alternative is a single tall enough storage tank so that different water temperatures get layered, then you don't need 2 (or 3) physically separate tanks. The upmost part of the tank, just below the domestic hot water heat exchanger pipes would have direct electric heater elements installed for those days when it's too cold outside for the poor compressor to make +55..+60degC water which you really want to have to prevent legionella in DHW. But most of the year in French climate, the compressor would be doing +60degC just fine.But, OP said they have low temperature radiators so the difference to underfloor circuits might be low enough so that the compromise from just shunting down the floor circuit is not too bad, in the end if SCOP goes down from 3.27 to 3.15 then who cares if you have simpler and cheaper installation. And for those not afraid of tinkering (and a tiny little bit of noise), adding PC fans to the radiators indeed would work to reduce the water temperature needed.

author: tszaboo
author_rank: Super Contributor
timestamp: February 19, 2024, 08:00:20 pm
content: Quote from: zilp on February 19, 2024, 05:51:13 pmYou see, this is where everything falls apart. I got 1 KWh of solar today on my panels, while regularly get 25KWh during the summer.If you turn the 1KWh into heat with a heatpump, you get 4-5 KWh of heat. If you do the same with P2G, for a summer day you get ~15KWh, if you burn the methane. If you burn the methane in a power plant,anduse a heatpump to heat your house, from the same summer day, you get ~60kWh heat.Quote from: zilp on February 19, 2024, 05:51:13 pmNobody talked about carbon capture. It's a farce, on the scale of solar roadways, and it's never going to work. But the same goes for "net zero" it's bullshit real world doesn't work that way. We don't have to emit zero CO2, we just have to be more efficient in the emissions, and do it in a way that doesn't cripple the economy completely. That's what net zero would do and the WEF if we let them.Even if you had a magical hat, and pulled out hundreds of millions of heatpumps, we wouldn't have the capacity to install them, and when we did, we wouldn't have the necessary power plants supply it.P2G has the largest effect with the least amount of effort. It's the hybrid car of electricity. And it's going to happen whether or not you like it, naturally, because it makes sense market wise. You make profit with it, since electricity is sometimes free, and CO2 has negative price. The banning of fossil fuels for home heating is the government again interfering with our life (they did that here), policies by people who have no basic understanding of the issue. I just watched a youtube video, American politicians on a committee (who were making a bill) were asked how much CO2 is in the air, and their answer was 3-5%. And these idiots are supposed to tell us what to do.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 19, 2024, 08:19:28 pm
content: I have been looking at the temperature data in my database of the last couple of months and see that the radiator in the worst room can keep up with 40C on the input and outside temperature ~-2C. It does not clime up to the set temperature, but also does not drop below the trigger point. So with continuous pumping 40C water through the system it might be fine on the coldest days.This season we only had 4 nights with temperatures below -4C on my outside sensor. Since it is place against a house wall in a secluded place it is not very accurate and the real low might have been below -6 according to the weather reports.But still not a lot of really cold days.I'm going to do an experiment the next couple of weeks where the water temperature on that radiator is limited to 35C and see if it will keep the room on temperature. Is just a simple change in the database done via my website to configure the system.

author: zilp
author_rank: Frequent Contributor
timestamp: February 19, 2024, 09:19:43 pm
content: Quote from: tszaboo on February 19, 2024, 08:00:20 pmNah, best case 36 to 45 kWh, assuming the same COP of 4 to 5. Gas power plants have terrible efficiency. First, you lose 40% in the conversion to methane, then you lose another 40% when burning it in the power plant, so the round trip loses 64% of the energy. And that is with the best, most modern combined cycle power plants, simple gas power plants have ~ 30% efficiency, so you would lose 80% of the energy. And also, that is ignoring the energy expended in order to compress the methane for storage and afterwards for expansion.Also, I don't really get what your point is here. I mean, that is exactly what I wrote would be a part of the optimal approach!? Obviously, we will be burning P2G gas when both sun and wind don't supply enough power in order to keep heat pumps running. Or are you suggesting that it would be more economical to use electricity from such a lossy process rather than wind power that can be used directly when that is available?!Also, the coldest days tend to be sunny, BTW. When you have a closed cloud cover, that keeps the heat in. When there are no clouds, that's when it gets cold.Quote from: tszaboo on February 19, 2024, 08:00:20 pmI have news for you:https://www.eevblog.com/forum/chat/what-is-the-real-story-around-heat-pumps/msg5343137/#msg5343137Let me quote:Quote from: tszaboo on February 19, 2024, 10:48:44 amSo ... I guess "Nobody" is an alias of yours?Quote from: tszaboo on February 19, 2024, 10:48:44 amI am not sure what your point is here!?Quote from: tszaboo on February 19, 2024, 10:48:44 amWhat makes you think that we'd have the capacity to install 500 TWh annual solar and P2G capacity? (Well, for Germany, I assume the situation would be similar in the Netherlands, just scaled down.)But also ... yeah, we totally have, and obviously so. Heating systems last on average, say, 20 years. So, every year, 5% of all heating systems are being swapped out, and we do have the manpower for that. Now, you replace it with a heat pump instead of a new gas burner, and in 20 years, you are done. At the same time, you keep building out renewables. Now, thanks to heating with heatpumps, the primary energy demands shrinks significantly, and you only need to add 125 TWh in order to replace the 500 TWh of natural gas. And as that whole thing progresses, the CO2 emissions go down continuously.Quote from: tszaboo on February 19, 2024, 10:48:44 amHave you even read what I wrote? I mean, yes, P2G will happen. I wrote as much. In fact it is already happening. But the idea that we will add 3.5 times the renewable build-out we currently have plus huge P2G capacities in order to then feed the resulting gas to home heating systems at a large scale because that makes sense market wise vs. installing heat pumps ... that's just insane. And no, you still don't make a profit by building a huge chemical plant that converts energy into a more expensive form just because "electricity is sometimes free". That is not how any rational investor calculates expected returns.Quote from: tszaboo on February 19, 2024, 10:48:44 amErm ... wasn't that the point of haveing a government, that it bans people hurting other people?! So ... what's your complaint there?!Quote from: tszaboo on February 19, 2024, 10:48:44 amOK ... and how are some clueless US politicians relevant to anything you are saying here? Is there any logical connection between "some US politicians have said dumb shit" and "therefore, P2G is an economically useful path to zero CO2 emissions in the Netherlands" or "therefore, heat pumps aren't a useful solution for the Netherlands"?

author: zilp
author_rank: Frequent Contributor
timestamp: February 19, 2024, 10:15:31 pm
content: Quote from: pcprogrammer on February 19, 2024, 08:19:28 pmIf you haven't yet, you maybe want to also add sensors to the return pipes, as the spread is required to calculate the energy going into a loop. If the return adjustment valves have a built-in flow meter (probably?), that would be all you need to calculate the power at least roughly. Also, it gives you an idea as to how much the power can be increased with increased flow.

author: tszaboo
author_rank: Super Contributor
timestamp: February 19, 2024, 11:05:12 pm
content: Quote from: zilp on February 19, 2024, 09:19:43 pmSo ... I guess "Nobody" is an alias of yours?That's not carbon capture. Carbon capture is a very inefficient process where they take CO2 from the atmosphere and compress it down. This is taken from an output of a power plant.Quote from: zilp on February 19, 2024, 09:19:43 pmYou need 125 TWh during the winter, from renewable, without mass storage. Good luck with that. From solar alone, it takes maybe 25 times as much panels to have the same capacity as during the summer. Not to mention the simple fact that the sun doesn't shine during the night, so what's your plan for that, battery storage? You are waaay off, because you calculate in watthours per year instead of watt of installed capacity. You cannot put electricity in a bucket. I hope this image will tell you what the problem is. If it doesn't then just think about the reliability of a completely renevable electricity based heating system. Meanwhile you can store as much gas, as you want.

author: nctnico
author_rank: Super Contributor
timestamp: February 19, 2024, 11:26:53 pm
content: How energy efficient would it be if we all move from north to south & vice versa twice a year in order not to need heating?

author: zilp
author_rank: Frequent Contributor
timestamp: February 20, 2024, 01:40:22 am
content: Quote from: tszaboo on February 19, 2024, 11:05:12 pmIt's just that that is exactly what carbon capture is:https://en.wikipedia.org/wiki/Carbon_capture_and_storageWhat you apparently mean is usually called carbon removal:https://en.wikipedia.org/wiki/Carbon_dioxide_removalQuote from: tszaboo on February 19, 2024, 11:05:12 pmI mean ... are you really unaware that wind power exists? Especially so, given that I have already told you that the yield curve of wind power is inverted vs. solar, so ... why the fuck are you now presenting a graph of solar yield?! Yeah, solar won't provide the power we need for heating in winter, who would have thought?!Quote from: tszaboo on February 19, 2024, 11:05:12 pmI mean, I guess you don't know this, so: The wind does indeed blow during the night. You can test this yourself by going outside during the night if you don't believe me.Quote from: tszaboo on February 19, 2024, 11:05:12 pmNo, I am not waaay off, just because I simplify things a bit. Obviously, we don't need just any random 125 TWh at arbitrary times. For heating, we need primarily wind power. And possibly some hydro power, where possible. Then, we need to make more biogas for storage and use in gas power plants (Germany composts most of its organic garbage, so there is quite a bit of potential there if we were to ferment it instead). And then some P2G for the gaps. Some of that probably imported from elsewhere.What certainly does not make sense is to instead install 700 to 800 TWh of solar capacity plus the matching P2G plants in order to generate and store 500 TWh of methane for use in gas fired home heating systems during the winter.Quote from: tszaboo on February 19, 2024, 11:05:12 pmGiven that there is no wind power mentioned in that image ... no, it obviously doesn't?Quote from: tszaboo on February 19, 2024, 11:05:12 pmWho cares that you can store as much gas as you want (which, by the way, isn't true either - currently existing storage volume in Germany for natural gas is not sufficient for the amount of natural gas Germany burns during a (cold) winter, for example) if it is more expensive than the alternative?Also, a completely renewable electricity based heating system is perfectly reliable. Because P2G is a part of the equation. It would just be dumb to run it all on P2G exclusively, and even dumber to just burn it in heaters, instead of extracting the majority of the required heat energy from the environment (thus obviating the need for storage), using primarily cheap wind energy to drive the process (also doesn't need long-term storage), and then using expensive P2G electricity when that isn't sufficient to make the whole thing reliable.Installing hundreds of TWh of solar on every roof in order to avoid installing heat pumps doesn't solve any problems, not even the man power problems.,

author: Siwastaja
author_rank: Super Contributor
timestamp: February 20, 2024, 07:23:05 am
content: Quote from: pcprogrammer on February 19, 2024, 08:19:28 pmNote that in need of varying distribution temperatures, if most of the house could use lower distribution temperature and it's just one room which needs higher, it will likely be more energy efficient to just run the whole system at the lower temperature and add a small extra direct electric heater to the room in question; especially if you can allow the room to temporarily cool down a bit.Quote from: pcprogrammer on February 19, 2024, 08:19:28 pmThis is still all easy-peasy to any half-decent air-to-water heatpump. I mean, my cheap heatpump is still doing quite acceptably (COP well over 1.5) at -15degC out / +40degC water. At my place it really starts to struggle i.e. need extra source of heat at -18 / +42, at which point marginal COP is 1.0 (that of added power) and actual COP not much over 1.0.It's a nice micro-optimization if you could lower the distribution temp to +35 but this is not a dealbreaker question.I was thinking about the noise. Ground source heatpump produces compressor noise, air source unit fan + compressor noise. The fan noise is almost never heard inside, unless you have something like a vent hole right next to the unit; it's the compressor noise that's bad. So the ground source pump is not necessarily completely silent to you either. If it's in cellar, made of concrete or stone, it will be completely silent of course. OTOH, if your house has brick walls and you pick a wall with no nearby windows or vent holes, and air source unit is ground mounted (not wall mounted) then it will be completely silent, too. One option which is not unrealistic at all, and applies equally to ground and air source units, is to improve the sound insulation. Compressor is normally wrapped in soundproofing (and thermally insulating) material, but the sheet metal case tends to have completely uninsulated spots which sometimes even tend to resonate, adding some bitumen-based sound insulation boards is not too far-fetched. And of course mounting the unit with dampers to prevent vibrations from propagating to the mounting base.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 20, 2024, 07:46:59 am
content: The De Dietrich heat pump for geothermal has a lot of sound insulation by the looks of what is given in the manual, and if needed additional sound insulation can be added to the basement.The question about performance has been satisfied and it is clear that there won't be that much difference between air to water and ground to water, so fear of sound is now basically our only choice factor.I'm also looking in to the possibility to control the heat pump with my own system, and that seems to be a bit tricky due to proprietary interfaces and protocols.

author: tszaboo
author_rank: Super Contributor
timestamp: February 20, 2024, 07:56:39 am
content: Quote from: zilp on February 20, 2024, 01:40:22 amHonestly your straw man arguing style is very exhausting to reply to. A few things that make your plan unviable is the simple facts that during summer there will be so much excess electricity, thats not even funny. Your own government is betting on power to gas, with short term plans for a 100 TWh a year.And banning fossil fuels and forcing people to install heatpumls is again the government forcing something on the people. But there has been enough research on the subject, so instead of typing here a wall of text like you, I'm just going to link those studies.https://www.google.be/url?sa=t&source=web&rct=j&opi=89978449&url=https://cris.vtt.fi/files/53434850/1_s2.0_S0306261921010643_main_1_.pdf&ved=2ahUKEwjz-ejbtrmEAxWpgf0HHV51A0E4ChAWegQICBAB&usg=AOvVaw0ryS1moGd9X6JepJADaAOX

author: Zero999
author_rank: Super Contributor
timestamp: February 20, 2024, 09:26:40 am
content: I appreciate there's a political element to this. Governments are try to push heat pumps, in favour of oil and gas, to cut emissions. Understandably many people are fed up because they don't like being told what to do, which is why there's some push back against heat pumps. Personally speaking, I won't get one in the foreseeable future, because it isn't economical for me. Natural gas is much cheaper than electricity, even taking into account the lower energy consumption, it doesn't add up. I don't have any problem with them and certainly aren't against the idea of getting one in the future. Heat pumps are viable where electricity is cheap, such as near a hydroelectric or nuclear power station. Areas where electricity is expensive need more investment in nuclear power, then people will choose heat pumps for economic reasons.Politics aside, are there heat pumps which use natural gas or oil, rather than electricity? It won't give the same COP but might be more economical. That might also suit me, although my energy usage is fairly low, so not worth it, until I need a new boiler.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 20, 2024, 09:31:32 am
content: Quote from: pcprogrammer on February 20, 2024, 07:46:59 amLook at terms like "EVU" or "smart grid" or "SG" or "SG-ready", which is a simple two-bit digital on/off control, allowing increase/decrease of setpoint. If even that isn't supported, then you most likely still have a simple on/off logical control you can interface to, and possibly another to prevent usage of aux resistive heating.No one actually interfaces the RS485/CAN buses of these heatpumps, even we doing this thing professionally have postponed such feature creep and still offer simple on/off control as the primary means and dedicated our efforts elsewhere (e.g. support gazillion of solar inverters instead of gazillion of heatpumps).One option is to use relays to add resistors in series/parallel with the thermistor used to by the heatpump to measure reservoir tank temperature, this way you can cheat setpoint finetuning without having to figure out an interface to actually control the setpoint (or more specifically, curve parallel shift).Be careful with your control, though - if you prevent heating for too long, creating large dip in temperature, then after releasing the control the heatpump's internal logic might decide that using resistive support heating is a great idea, ruining your COP.

author: nctnico
author_rank: Super Contributor
timestamp: February 20, 2024, 09:48:29 am
content: Quote from: zilp on February 20, 2024, 01:40:22 amNot methane but hydrogen. Plants to convert electricity to hydrogen are being build right now. First to turn 'useless' electricity into hydrogen for other purposes (including mixing with natural gas to reduce the amount of natural gas being use), but soon also to convert hydrogen back into electricity. Batteries just aren't going to cut it for seasonal storage. Not by a long shot.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 20, 2024, 10:06:53 am
content: Quote from: Siwastaja on February 20, 2024, 09:31:32 amGood options to look into. For De Dietrich I found that there is an opentherm to modbus converter option. Also found some French forum about it and might be able to get some more information when I register there. Downloads are restricted for me as is.

author: m k
author_rank: Super Contributor
timestamp: February 20, 2024, 10:34:37 am
content: We have a small direct electricity radiator that is rattling.It's close to both units of the air to air heatpump but it's also rattling when heatpump is off, I think.Plus side is that it's easy to adjust, after successful adjustment it's still vibrating but silently, I can still clearly feel it.It's a completely different ball game if geothermal pump is vibrating through the building.One of those things where personal sanity may be questioned.Our house has few resonating places but all are higher pitch and avoidable.One is a corner, or near of it where upper part of a hearing band whine can be heard, or I can, moving a head about a head size and it's gone.Generally I hear some kind of whining all the time, occasionally also short and probably universal tinnitus stylish things.If I start listening I'm still hearing an old CRT TV, maybe it's in my head, at least all machines, that I know of, are long gone.When that tinnitus thing happens, is mild or lower and turning head is giving it a direction I know that washing machine is ready.It's also not unheard of that outdoor unit of a neighboring heatpump is generating ground noise, so good vibration absorbing is important.We can faintly hear when neighbor is dropping logs to down stairs, most likely onto a stone floor of some sort and maybe 40m away.Air to air heatpump control through self made remote controller was a thing here a decade or so ago, now there are more possibilities.Air to water machine has much more settings.So my opinion is that connecting it must be supported by the manufacturer.

author: zilp
author_rank: Frequent Contributor
timestamp: February 20, 2024, 11:08:42 am
content: Quote from: nctnico on February 20, 2024, 09:48:29 amThat doesn't contradict what I wrote. Yes, electrolysis/P2G plants will be built and are being built right now here in Germany (which I already mentioned). But we will not add 700 TWh of solar generation capacity plus the same P2G capacity in order to generate sufficient methane or hydrogen to keep running gas fired heaters, for the reasons that I have explained at length.Also, hydrogen isn't all that useful for seasonal storage either because its energy density is way lower than that of methane. As I already mentioned, our current natural gas storage capacity already isn't sufficient to store what Germany currently uses through the winter. If we stored hydrogen instead, that number would be significantly lower still. Which is fine-ish if we switch to heat pumps and therefore massively reduce the required amount of primary energy and then use that storage to feed gas power plants to smoothe over gaps in renewable generation, but not for keeping gas fired heaters in any significant numbers.Really, though, the primary use of hydrogen (and methane synthesised from it) will be for industrial processes that need hydrogen or methane as a chemical input, or for industrial processes that need temperatures that you can't reasonably reach without fire.The idea that we'll mix renewable hydrogen into the natural gas supply also is largely nonsense. I mean, it's not that that might not happen, but it's certainly not a long-term solution, but likely more an option to make use of excess hydrogen, especially during the transformation, in case electrolysis plants get completed faster than industry switches over their processes from fossil inputs to hydrogen or P2G methane, or where separate hydrogen pipelines don't exist yet.Because of the lower energy density of hydrogen, as you increase the fraction of hydrogen in the natural gas supply, the transport capacity of your distribution network decreases. If we add only 20% of hydrogen (a number often claimed as possible without modifications to the network), that decreases the network capacity by 14%. And at the same time, that only decreases natural gas demand (and therefore CO2 emissions) by ~ 7%. Which is better than nothing, granted--but obviously not really a solution.Possibly, that could work out if we swap out 90% of gas fired heaters for heat pumps, thus massively reducing the demand on the network, so that we can then switch it to 100% hydrogen and still have sufficient transport capacity. But in addition to the probably relatively high price of green hydrogen, that would also mean that the newtork maintenance costs now would be distributed among a tenth of the customers we have now and thus would increase tenfold per customer. Which doesn't exactly make things more economical for the customer. Also, we'd probably have to swap out compressors and stuff, which makes for additional costs that that remaining customer base would have to pay for.

author: JohanH
author_rank: Frequent Contributor
timestamp: February 20, 2024, 11:47:09 am
content: Geothermal heatpumps with variable speed are very silent. I have a small Nibe F1255 (6 kW) and a 170 m borehole. It has a Mitsubishi BLDC motor that runs between 20 and 120 Hz. By default it's limited to max 102 Hz. I tried increasing the output and it becomes a bit noisy at 120 Hz. As it is now, it's more quiet than the old oil burner. The house is 145 m^2, with about a third in-floor heating and the rest radiators. I've changed to bigger radiators after installing the heatpump. The floor is shunted from the radiator system. This is of course not optimal. I haven't looked up recent numbers, but in 2021 the heatpump used 4700 kWh electrical energy that it turned into 13500 kWh heat energy and 4000 kWh warm water. In total 17500 kWh heat energy. This makes an SCOP of 3.7. This is not bad for a house from 1927 with some parts lacking good insulation. On really cold days, such as this winter with -30°C, the heatpump doesn't make enough power, so it's intermittently turning on the resistive heaters. It doesn't do this when warmer than -25°C. I could turn up the power, but it seems that the 170 m borehole is not deep enough. I don't dare running the hole colder. As of now, at prolonged max power, the hole gives -1°C in with -5°C out from the compressor (at lower power levels, incoming returns to plus degrees and delta is about 2°C). With increased power output, there is a risk for freezing around the hole, in worst case creating damage. In hindsight, a 190-200 m borehole might have been better and wouldn't have costed much more. Around here, 220 m boreholes are common.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 20, 2024, 11:56:29 am
content: For our situation the two boreholes are quoted at 85m deep to be sufficient. Have to wait and see what the other company suggests.

author: tom66
author_rank: Super Contributor
timestamp: February 20, 2024, 11:59:26 am
content: What really disappoints me is in the UK we are still building homes without heatpumps. Gas boilers and gas networks continue to be installed.A geothermal heat pump is difficult to install for an existing home because you need an expensive crane to come in to one home just to drill the borehole. Depending on the ideal location of a borehole this may be impractical. In any case, it's typically around £20,000 -after- a grant to have such a system installed, even though the borehole is likely to cost only a little more to drill.This makes the payback time of such systems nearly infinite.If that was all done before the plots were even built then we'd save a lot of money on that alone whilst giving quite a practical heatpump infrastructure for many. Since the ground (at least in the UK) is typically around 10-15C year round, geothermal heatpumps typically have higher CoP and less concern over cold weather performance (they work nearly as well at -10C as they do at +10C outdoor.)

author: coppice
author_rank: Super Contributor
timestamp: February 20, 2024, 12:00:09 pm
content: Quote from: nctnico on February 19, 2024, 11:26:53 pmThere is a reason migration is a common trait in animals. The more mobile they are (e.g. birds) the more energy they seem to expend on migration for the benefits in brings in other ways.

author: coppice
author_rank: Super Contributor
timestamp: February 20, 2024, 12:07:46 pm
content: Quote from: tom66 on February 20, 2024, 11:59:26 amThat's not the core problem. The core problem is building land has become such a scarce resource that houses are built to get the maximum use of the space available. Also the building has to be constructed cheaply, so the final price, including the land, is somewhat affordable. This is incompatible with heavy insulation. In the 1930s land, in even suburban London, was so available even the cheapest houses could have huge gardens. Now luxury houses have tiny gardens. No space == no room for thick effective insulation. No space == no room to bore for geothermal heat. No space carries an energy burden.

author: zilp
author_rank: Frequent Contributor
timestamp: February 20, 2024, 12:26:55 pm
content: Quote from: Zero999 on February 20, 2024, 09:26:40 amYep, there are. My understanding is that the Netherlands are betting on natural gas driven heat pumps quite a bit.But of course that is only economical because the externalities of CO2 emission are subsidized by other people. Less so than with purely natural gas heating, of course. But it's a risk to consider, in that chances are that the subsidy will stop at some point and all the externalities will be internalized, at which point that will stop being economical. And that especially if you are the exceptional user of such a system and thus don't have the lobbying power to force other people to subsidize your CO2 emissions. And also, if everyone around you switches to electrically driven heat pumps, chances are that the fixed costs of a gas supply line will increase significantly as the few remaining users will have to pay for the keep-up of the whole distribution infrastructure.

author: coppice
author_rank: Super Contributor
timestamp: February 20, 2024, 12:32:56 pm
content: Quote from: zilp on February 20, 2024, 12:26:55 pmWhen I was at a grid conference and exhibition in Amsterdam about 10 years ago there were at least 2 vendors pushing gas powered heat pumps for domestic heating. They were claiming about 1/3 of the gas use compared to a conventional boiler in the Netherlands environment, which seemed optimistic. I can't remember what sort of water temperature they were basing their claims on.

author: nctnico
author_rank: Super Contributor
timestamp: February 20, 2024, 01:23:53 pm
content: Quote from: zilp on February 20, 2024, 12:26:55 pmNo, these are hybrid boilers. If the heatpump can't provide enough heat, the gas burner is turned on. This leads to needing a much smaller heatpump because it doesn't need to cover the extreme cases. Still, the problem with heatpumps is the outdoor noise. Especially in densily populated areas. In the NL quite a few cities are installing or upgrading district heating systems. With such a system you can combine various heat sources and heat a large part of the homes in a large area.

author: coppice
author_rank: Super Contributor
timestamp: February 20, 2024, 01:30:31 pm
content: Quote from: nctnico on February 20, 2024, 01:23:53 pmThere are probably some of those, but the vendors I referred to above were really pushing gas powered heat pumps in the Netherlands. Maybe we could go back to the old steam engiine powered heat pumps of 19th century refrigeration.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 20, 2024, 01:47:57 pm
content: Quote from: nctnico on February 20, 2024, 01:23:53 pmThis is the sensible thing to do. Actual gas/oil driven heatpump only makes sense if electricity is always expensive and sparse. In reality most of the time there is no shortage of production and grid is pretty clean thanks to all the renewables, in almost any country. Actual percentage of "prefer electricity" varies per region being maybe 98% somewhere and just 80% somewhere else. By using the heatpump with relatively cheap and plentiful electricity 90% of the time, at high COP in modestly cold conditions, and burning oil/gas/wood/whatever for 10% the time in traditional simple burner, when it is too cold such that COP would plummet anyway, you get the energy consumption advantages of the heatpump, can use green energy produced by wind and solar power,andutilize the excellent storage capability of fuels.This is also why I suggest the OP does not dismantle the operational wood burning system they have, even if currently planning not to use it. Even if just for one week per year, it could make a difference. I burn oil/wood for about 1-4 weeks per year depending on year.

author: zilp
author_rank: Frequent Contributor
timestamp: February 20, 2024, 02:28:42 pm
content: Quote from: tszaboo on February 20, 2024, 07:56:39 amWould you mind pointing out a straw man argument of mine?Quote from: tszaboo on February 20, 2024, 07:56:39 amHow so? Like, how much are we talking about? How do you know it's "excess"?Quote from: tszaboo on February 20, 2024, 07:56:39 amYeah ... so?!Just to be clear: Your original claim that I am responding to is this:Quote from: tszaboo on February 18, 2024, 11:18:25 pmAnd 100 TWh would obviously be a joke if the plan were to keep gas fired heaters so "we don't have to replace the entire infrastructure of basically everything we own", given that gas fired heaters currently burn ~ 500 TWh in a year, and that that 100 TWh obviously is not exclusively for heating, which itself currently is only responsible for about a quarter of primary energy consumption, but rather also is intended to provide hydrogen and methane for the chemical and steel industry, for backup electricity generation through gas fired power plants for all elecricity supply (i.e., heating, EVs, industry, and other minor uses). So, the plan obviously is not to use P2G gas for heating in order to avoid switching to heat pumps, the plan is to use P2G to make the electricity supply reliable that then is supposed to feed heat pumps and EVs.To achieve anything close to "not replacing the entire infrastructure" with P2G, we'd have to install 1 to 2 PWh of solar power and P2G plants, quadruple our gas storage volume, ... essentially: Put more resources into adding all of that additional infrastructure than would be needed to replace all the inefficient systems, just to avoid replacing those inefficient systems.Quote from: tszaboo on February 18, 2024, 11:18:25 pmYou do realize that that sounds incredibly dishonest, right?For one, here in Germany, noone is forced to install a heat pump. The law simply says that you can't exceed a certain fraction of non-renewable energy for newly installed heating systems. You are completely free in how you meet that requirement. I have no idea what the exact rules are in the Netherlands, though.But also, you are obviously just pretending as if you didn't know that the government is banning fossil fuels because you burning fossil fuels hurts other people. "Banning fossil fuels is the government focring something on the people" is about as sensible as "Banning putting cyanide in people's food is the government forcing something on the people" ... technically true, but also obviously intentionally playing ignorant as to the fact that this is done to protect other people's legitimate interests and not in order to harass you. If you feel harassed by the government banning you from hurting other people, maybe you should reflect on why that is.Quote from: tszaboo on February 18, 2024, 11:18:25 pmWould you mind at least giving a short summary as to what specific claim of yours you think that study supports and how you think it does so? At least from skimming through it, I don't get the impression that this study supports the idea that P2G will be the solution to just keep using the gas infrastructure as before.

author: tszaboo
author_rank: Super Contributor
timestamp: February 20, 2024, 03:28:34 pm
content: Quote from: zilp on February 20, 2024, 02:28:42 pmMaybe breaking down my replies sentence by sentence just to find something to criticize. It's a strawman argument style, when you don't take a comment as a whole but you try to poke holes in sentences individually. It's what you are doing right now.Quote from: zilp on February 20, 2024, 02:28:42 pmIn the Netherlands newbuilds cannot be connected to the gas network, and by 2026 if your heating craps out you are forced to install heatpump or go homeless. There are other countries.That lefty bullshit about natural gas "hurting other people", please take that to your support group, nobody is interested in that on an engineering forum. You cannot just wish yourself into a better future.Quote from: zilp on February 20, 2024, 02:28:42 pmLast comment it was 700 TWh, I guess two comments from now it's going to be 10 PWh of solar, and then 100 PWh.Yet you still failed to make a few very simple calculation.1) How much TW of electricity generation you need to power the heatpumps during the winter. You will find that it's ridiculous compared to any other plan.2) Where do you get the approximately 2 trillion EUR to change 40 million households to use geothermal.3) What do you do when you realize that the rest of the world doesn't care one little bit about your carbon neutral plan, they keep on using fossil fuels, and there is no way to convince them, because they either burn fuel, or their children will be left without food. Germany produces 2% of the global CO2 emissions, if it would sink to the bottom of the ocean tomorrow, it wouldn't make a dent.You need to make cheap, storable, high concentration, renewable energy available for everyone if you want to change anything. And something that turns a profit. Which is exactly what P2G does, it turns rooftops, unused land and CO2 and so on into money.

author: coppice
author_rank: Super Contributor
timestamp: February 20, 2024, 03:51:42 pm
content: Quote from: tszaboo on February 20, 2024, 03:28:34 pmHow are their grid tributary upgrades going for all those streets where the underground cables were installed at a time of light consumer loads? Most places like to talk about grid backbone issues, but the last mile is going to be staggeringly expensive.

author: tszaboo
author_rank: Super Contributor
timestamp: February 20, 2024, 04:27:21 pm
content: Quote from: coppice on February 20, 2024, 03:51:42 pmI don't know, you should ask our excellent government who made the law. The only thing driving them was the extreme hatred of natural gas.I also don't know what will happen with people in apartments, cities. I guess it will look like 90s socialist office buildings where every office had their own air-conditioning and you had dozens of airco units on the front of the building.

author: coppice
author_rank: Super Contributor
timestamp: February 20, 2024, 04:34:58 pm
content: Quote from: tszaboo on February 20, 2024, 04:27:21 pmThe UK and the Netherlands both got a lot out of North Sea gas. The UK squandered this bonus, as it did later with oil, propping up a failing economy. We used to see quite a lot of coverage about how the Netherlands was doing well from their gas bonus, although a lot of it seemed to be going into unsustainable social programs that would lack funding when the gas ran out. Are they just sore that the good days are over?

author: Zero999
author_rank: Super Contributor
timestamp: February 20, 2024, 05:58:25 pm
content: Quote from: Siwastaja on February 20, 2024, 01:47:57 pmThat certainly isn't the case where I live. Electricity is nearly four times as expensive as gas.Renewables are often unavailable, when lots of power is required for heating, which is normally on cold, calm winter's days in much of Northern Europe, when a good proportion of the electricity will be generated with coal oil and gas.A gas powered heat pump would certainly be the cheapest way to heat my home, in terms of running costs. An electric heat pump would cost more to run, than my gas powered condensing boiler!

author: m k
author_rank: Super Contributor
timestamp: February 20, 2024, 06:29:46 pm
content: Quote from: coppice on February 20, 2024, 03:51:42 pmHere bedrock is visible here and there.People are also around and part of a year is cold.Water distribution.It used to be so that first bedrock is exploded away and later put on the pipes.Maybe there still is no other way but everything is practically ready.Luckily electricity can stand some coldness.Yes, but here lines below tree tops to last transformer must be away from storms.Many times company policy used to be like dig your own ditch.Maybe they can figure out a deal this time, in case some of old ditches are too small.Jan-24 electricity bill has arrived, the month was cold, partially -30C, then almost two decades old air to air pump can't help, so direct electricity and wood.(the pump has most likely lost some liquid since it can't do much when temp goes near -15, it used to be fine a bit under -20)Bill is 400€, energy part being a bit over half and 1567 kWh, other parts are transfer and taxes.Now it's few degrees below freezing and the pump is chilling and keeping up using a bit over 400W.Ventilation is doing its part but stove is not even warm, not cold either.E,temp, indoor temp went somewhere, it's 21C.

author: nctnico
author_rank: Super Contributor
timestamp: February 20, 2024, 07:38:57 pm
content: As a sidenote: I have free wall-heating in my office. The neighbours next door have sound-proofed their attic which I appreciate. But -according to them- (*) they put the heating radiator partly behind the sound proofing so they have to run it at full blast. It heats my side of the wall to about 30 degrees at the warmest point. Oh, and the wall actually isn't a single wall but a decoupled one. It is 9 cm of concrete, a 9cm air gap and then another 9cm of concrete. I do not want to know how high their heating bill is...I have to open a window to cool my office down in the winter.* It took me a while to figure out the neighbours where causing my wall to get warm. My computer is under the desk at roughly the warmest spot so initially I thought that it was my computer heating the wall but it just didn't make sense to me from an energy standpoint. After using the thermal camera which showed the hot spot is way above the computer it started to dawn to me it had to be the neighbours.

author: zilp
author_rank: Frequent Contributor
timestamp: February 20, 2024, 08:07:29 pm
content: Quote from: tszaboo on February 20, 2024, 03:28:34 pmYou do understand that a strawman argument is when you misrepresent the other party's position, right?You did notice that in this answer, you did not point out any instance of where I misrepresented your position, right?Poking holes into sentences individually is not a straw man argument.So, do you have anything to back up your accusation, or do you not?Quote from: tszaboo on February 20, 2024, 03:28:34 pmOh, now we are at the "insult the other person instead of arguing my position" stage of this discussion?Am I now supposed to call you a Nazi, or how does this work? I am sorry, I normally argue on the subject of the discussion instead of throwing insults at pople, so you will have to help me out a bit here.I take it that you aren't interested in actually supporting your position with any non-fallacious arguments?Quote from: tszaboo on February 20, 2024, 03:28:34 pmOK?! I mean, sounds reasonable, but no idea why you are throwing that in here?!Quote from: tszaboo on February 20, 2024, 03:28:34 pmNo, it wasn't, you just aren't paying attention. The previous 700 TWh was for heating purposes only, because that was the topic of the discussion. This was for the total energy demand.Quote from: tszaboo on February 20, 2024, 03:28:34 pmCompared to what other plan?Quote from: tszaboo on February 20, 2024, 03:28:34 pmDo you have a source for that number, and why that would be needed?Quote from: tszaboo on February 20, 2024, 03:28:34 pmWhy would this hypothetical scenario be something that I should concern myself with?Quote from: tszaboo on February 20, 2024, 03:28:34 pmOK ... so? Like, I mean, that statement sounds reasonably correct ... but how is that relevant?Quote from: tszaboo on February 20, 2024, 03:28:34 pmOK?! Here is a question for you: And what if you can't? You saying "You need to" is not exactly something that reality has to obey, is it?Like, you do see how that is a completely useless statement, right? It's one thing to say "if we had X, then that would solve the problem". But what is the point of saying "we need to have X"? If we can't have X, it's completely useless to say that we need it ... in particular when that in itself is actually a completely unsubstantiated claim. If there is no profitable way to solve climate change, that doesn't make climate change not a thing, right? So, if there is no profitable way, then demanding that the solution must be profitable is just going to doom us all, right?Quote from: tszaboo on February 20, 2024, 03:28:34 pm... OK?! I mean, you still haven't addressed all the reasons that I have given as to why I have my doubts about that, but OK, let's assume that you are right: So, how does that mesh with your call for the government to do something about that? If that is profitable business, then why would the government have to do anything about that?! Is there anything that the government is doing that is preventing investors from building these plants that supposedly would be so profitable?!

author: Marco
author_rank: Super Contributor
timestamp: February 20, 2024, 09:11:06 pm
content: Quote from: nctnico on February 20, 2024, 01:23:53 pmIt's all done with huge main-road excavation though ... that really limits the reach and the contractors who can do the work.It was a huge missed opportunity to not combine fiber rollout with district heating AND EV charging (just access points, don't have to put chargers in immediately). 10's of billion Euro mistake. Now the fiber is in, the sidewalks are far less suited to new infrastructure.

author: Someone
author_rank: Super Contributor
timestamp: February 20, 2024, 10:55:02 pm
content: Quote from: Zero999 on February 20, 2024, 09:26:40 amExcept your idea of "cheap" is already biased by politics. Gas in the UK is being sold to consumers at a suspiciously low rate compared to electricity. Trigeneration or running your own micro gen should be the answer in those conditions. The unusual situation where gas is much cheaper per unit energy than the open market has settled on.

author: Someone
author_rank: Super Contributor
timestamp: February 20, 2024, 11:19:17 pm
content: Quote from: coppice on February 20, 2024, 12:07:46 pmSurface area is the key, although the ground looks like an infinite heatsink to a single user with a very slow time constant, over human time scales and densities it doesn't work without active recharging:https://www.withouthotair.com/cE/page_302.shtmlBut there seem to be (recurring) users on this forum who just can't understand basic physics:https://www.eevblog.com/forum/chat/what-does-drilling-a-hole-for-water-cost-here-in-europe/?all

author: Marco
author_rank: Super Contributor
timestamp: February 20, 2024, 11:21:19 pm
content: Since PV provides a glut of power in summer, recharging is hardly an issue.

author: themadhippy
author_rank: Super Contributor
timestamp: February 21, 2024, 12:32:37 am
content: QuoteAnd the gas companys still manage to make record profits,still the new golden hydrogen will change everything.

author: coppice
author_rank: Super Contributor
timestamp: February 21, 2024, 03:46:04 am
content: Quote from: Someone on February 20, 2024, 10:55:02 pmUK energy prices are rather twisted right now, but before the Ukraine war electricity was about 4 to 5 times as much as gas. Do you think that is unreasonable?

author: Someone
author_rank: Super Contributor
timestamp: February 21, 2024, 07:38:41 am
content: Quote from: coppice on February 21, 2024, 03:46:04 amIts an anomaly with the UK at an extreme:https://www.visualcapitalist.com/mapped-global-energy-prices-by-country-in-2022/Plotted below to quickly see the trends (NL is way off to the right as the opposite outlier, OP is in FR which is also well off the average trend).Gas is great for non-routine power plants (3:1 or so ratio to include all costs) and has higher value than electricity for some uses due to the inherent storage and high energy density possible. Anyone with access to gas below 3:1 ratio should be sending it to produce electricity and bring down their electricity prices (UK committed their population to long term supply contracts for nuclear??)

author: Zero999
author_rank: Super Contributor
timestamp: February 21, 2024, 08:29:11 am
content: Quote from: Someone on February 21, 2024, 07:38:41 amGas can only provide heat and when used to generate electricity, half of it is lost as heat.I still think a gas powered heat pump would be best for me in winter. Generating my own electricity from gas is an interesting idea though. I've thought of solar panels, but not that one.Quote from: tom66 on February 20, 2024, 11:59:26 amI should darn well think so, given electric heat pumps are more expensive to run, than gas boilers. If the government really want people to have heat pumps, they need to make electricity much cheaper, think nuclear, then people will be queuing up to get one.

author: Someone
author_rank: Super Contributor
timestamp: February 21, 2024, 09:37:09 am
content: Quote from: Zero999 on February 21, 2024, 08:29:11 amBy the time you're looking at a gas powered heat pump, a trigeneration setup isn't much further. But it's a bet on long term price of commodities given the lifespan/payback of such systems.

author: mfro
author_rank: Regular Contributor
timestamp: February 21, 2024, 09:53:40 am
content: Quote from: Someone on February 21, 2024, 07:38:41 amThat link shows prices as of March '22. Far from reality in Feb 24.

author: Zero999
author_rank: Super Contributor
timestamp: February 21, 2024, 10:06:58 am
content: Quote from: Someone on February 21, 2024, 09:37:09 amNo doubt it's possible to design a heat pump, which can be powered from electricity, as well as gas. It's just a case of adding an electric motor. It's definitely something I would consider, if my boiler were to need replacing.Quote from: mfro on February 21, 2024, 09:53:40 amThe copy of the energy bill I posted was for 2023 to 2024. For me gas is around a quarter of the price of electricity. I would have to be mad, to heat my house with anything but gas!https://www.eevblog.com/forum/chat/what-is-the-real-story-around-heat-pumps/msg5345987/#msg5345987

author: Someone
author_rank: Super Contributor
timestamp: February 21, 2024, 10:18:43 am
content: Quote from: mfro on February 21, 2024, 09:53:40 amExample of the wide ranging spread of electricity : gas pricing in the real world, so comments from the UK such as gas is 4:1 should be taken with the grain of salt befitting an outlier situation, and not generalised to the rest of the world.Feel free to put up some more recent figures, or older, or averaged, or whatever. What do you think has changed since those numbers were collected? Over here electricity is cheaper still and gas more expensive, heading further toward a 1:2 ratio.

author: soldar
author_rank: Super Contributor
timestamp: February 21, 2024, 11:11:40 am
content: Quote from: Zero999 on February 20, 2024, 09:26:40 amWell, yes and no but perhaps maybe... Things can get complicated.Where I am I think heating the entire house with the central gas boiler and radiator system would be cheaper. But...I do not need to heat the entire house and can manage quite well if I only heat one room where I spend most of my time. I suppose I could install some system to heat that single room with gas but it is not practical and I already have a split a/c heat pump system and I have to say it works really well and really cheaply.I have my own "manual algorithm" which I suppose I could somehow automate but basically it comes down to pump a lot of heat from outside when the outside temperature is higher outside because this increases efficiency. This means less stable temperature inside but I can live with that because it means less cost. If in the middle of the day it gets hotter than I need, so what? It is heat I am accumulating inside now that it is easy to get rather than in the middle of the night when it is much more expensive.My "algorithm" aims for minimum cost, not maximum comfort.

author: Miyuki
author_rank: Frequent Contributor
timestamp: February 21, 2024, 11:24:40 am
content: The problem with generating electricity on a small scale is that the cost does not scale linearly.And also big engines are easier to reach high efficiency. While big piston engines can reach over 50%, small generator ones are closer to 30% which might not be a big problem if you want the heat anyway.Then there is here the maintenance problem, every few hundred hours. And that noise issue.But gas-powered heat pumps might be a nice option for places with cheap gas, even with their low COP of 1.5 - 2.5, there can be a significant reduction in gas usage. I wonder why they are not more common at the domestic scale. Probably only a few places have suitable conditions to use them to be actively developed and manufactured.And with ever-dropping prices of solar panels, they probably won't be ever viable as they need to be powered by a heat source, so a compressor-driven heat pump is way more versatile and can get some help from solar even during winter.

author: m k
author_rank: Super Contributor
timestamp: February 21, 2024, 11:42:15 am
content: Our recent electricity prices have had few peaks.Last November some Norwegians gave us a high five.We have an electric sauna heater, many others also.Our heater is 6kW thingy and when it goes on electricity heating radiators are blocked, not enough fuses for all.But 16A wall jacks are still on and luckily I have few portable electric heaters with fans, luckily not too many.My average electricity for November was less than 4c/kWh.Our electricity network has two parts, the grid and its energy.You can buy your energy from where you want, but grid owner is always billing its part.Old electricity companies are many times county or many counties owned and hidden tax collectors.Means that electricity transfer cost is as high as it is legally possible, some of them may try to argue against.A comment after that November day from a grid operator.He estimated that during that time he learned every spot electricity customers in his grid.Some burned their main fuses multiple times, billing meter reported them.Story doesn't tell how those fuses were put back.Our possibly 3x63A grid fuses are from late 70's and "far away" outside, 3x25A mains switch fuses are under the switch and behind a sealed plate.

author: Zero999
author_rank: Super Contributor
timestamp: February 21, 2024, 11:48:16 am
content: Quote from: Someone on February 21, 2024, 07:38:41 amI forgot to say, that link shows gasoline prices. I'm talking about natural gas. I don't know of anyone who uses gasoline to heat their home int the UK. It's very heavily taxed.Quote from: soldar on February 21, 2024, 11:11:40 amWhere did I say you should do the same as I do?All I did was responded to a comment which implied that electric heat pumps are economical for most people, which I dispute. It certainly isn't the case for me.Engineering is all about selecting the most optimal solution, for a specific application. In my case a gas powered heat pump is the cheapest to run, but nowhere did I say that's the same for everyone. The original poster currently heats their home with wood, so an electric heat pump will certainly be cheaper, than the status quo.

author: soldar
author_rank: Super Contributor
timestamp: February 21, 2024, 12:12:13 pm
content: Quote from: Zero999 on February 21, 2024, 11:48:16 amWhere didIsay you said that? .... I did not and I cannot see how my post can be understood that way. Relax. We are all friends here.Quote"Most optimal"? Now, those are fighting words!

author: Zero999
author_rank: Super Contributor
timestamp: February 21, 2024, 12:29:46 pm
content: Quote from: soldar on February 21, 2024, 12:12:13 pmThe way you quoted me saying that gas is cheaper than electricity, could be taken out of context. When the rest of the post is taken into account, it's clear I was talking about my situation, not everyone's. I'm not saying this was intentional of course. It's easily done.QuoteIndeed and in this case, what's optimal can change over time. This is why I would be interested in a gas/electric heat pump, that way I'm not locked into using one fuel and can change, if electricity becomes much cheaper than gas in the future.Anyway, this thread has become too off-topic. The original poster just wants to know the pros and cons of replacing their current wood fired heating with a heat pump.I wonder if it's easy to power a heat pump from a gasifier. It aught to significantly cut fuel consumption. It's not something which you'll be able to purchase off the shelf, but is certainly doable from off the shelf components. I'm thinking of a gasifier powering a small internal combustion engine, driving an automotive air conditioning unit. You might have to change the refrigerate so something more suitable for heating than cooling, but it'll work. I don't know what COP you'll get, but it aught to be better than just burning wood.

author: nctnico
author_rank: Super Contributor
timestamp: February 21, 2024, 12:35:33 pm
content: Quote from: Marco on February 20, 2024, 11:21:19 pmIt is an issue as there is a relatively short peak power output from solar panels. A common solar panel setup with 12 panels, can deliver around 4kW of output for a couple of hours per day. So either you need a large heatpump capable of taking in 4kW of power and convert this into heat that goes into the ground (assuming the ground can absorb it quick enough) OR have a large battery pack which can smear out putting the energy into the ground over time. Neither is cheap / cost effective. And then you'll still need electricity to get the heat out of the ground again. Where is that coming from? My estimation is that conversion to/from hydrogen (in some form) you can store above ground is more cost effective.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 21, 2024, 01:21:48 pm
content: Quote from: Zero999 on February 21, 2024, 12:29:46 pmI don't mind, my question has been answered.Quote from: Zero999 on February 21, 2024, 12:29:46 pmI guess it would be quite the contraption that makes a significant amount of noise, and would still require wood to be hauled around.Still waiting for the second quote, but in the mean time I have found options for controlling, or at least read the De Dietrich heat pump with a RS485 interface. A lot of the info is in French, and unfortunately registering to the before mentioned site did not result in the ability to download the mentioned files. But I found a github repository with a python based solution, which gives the needed information.

author: coppice
author_rank: Super Contributor
timestamp: February 21, 2024, 02:10:54 pm
content: Quote from: Someone on February 21, 2024, 10:18:43 amPrices during a major international upset don't really mean anything about the long term. Some country's energy supplies were disturbed far more than others, so their price rises had a large spread. The chart you posted actually says UK home heating costs were up 3 fold that year. It says 10 cents/kWh for gas. That's less than I have been paying, but its about 3 times what I paid in 2021.

author: tom66
author_rank: Super Contributor
timestamp: February 21, 2024, 03:47:10 pm
content: Quote from: Zero999 on February 21, 2024, 08:29:11 amNot sure that they are more expensive to run. Basic maths assuming Ofgem capped rates.Gas = 7p/kWhElectric = 29p/kWhGas boiler efficiency (net) = ~85% under normal conditions. 90% best case but rarely achieved.Heat pump efficiency (net) = ~350% seasonal average.So per kWh of heat, the gas boiler costs 8.2p whereas the heat pump costs ... 8.3p.There may be some variation either side of these figures but in the UK alone, a heat pump should cost *about as much* as a gas boiler to run.Going on agile tariffs, like Octopus Tracker, may show more of a difference. Today's tracker costs are 3.69p/kWh for gas and 16.9p/kWh for electricity. Giving per kWh equivalents of 4.34p/kWh and 4.82p/kWh. But still, a pretty close parity, and the heat pump could easily win if the SCOP was better, whereas the gas boiler is already pretty much as efficient as it gets.The problem is that heat pumps cost so much more to install, so it doesn't really matter even if they cost, say, 2p less per kWh, the TCO doesn't add up if you assume 10 year lifespan before major refurbishment is required. The cost per kWh of heat needs to be half or less to make them pay off and even then, it's arguable as to how cost effective they are. And replacing a gas boiler costs ca. £2,000 whereas a heat pump costs at least £5,000 but possibly double that in the worst case.Really, heat pumps need to fall in price, that will make them a lot more affordable. I don't personally understand why they cost so much, but I haven't looked in depth at one.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 21, 2024, 03:59:27 pm
content: Quote from: tom66 on February 21, 2024, 03:47:10 pmBut gas boiler manufactures state 103 to 107% efficiency for the condensing systems.(How to fool your customers)I don't see either why the heat pumps need to be so expensive. A small car can probably be bought for the price of the De Dietrich GSHP 12 MR-E. (11066,95 Euro including 5,5% TVA or in English VAT)

author: Zero999
author_rank: Super Contributor
timestamp: February 21, 2024, 04:04:38 pm
content: Quote from: tom66 on February 21, 2024, 03:47:10 pmYour figures for an electric heat pump are wildly optimistic because you used the seasonal average of 350%, when you should use the COP, when it's going to be working hardest and consuming the most power, which will be much lower.A gas powered heat pump is a more economical solution. It wouldn't cost much more and would be cheaper to run, so would eventually pay for itself.

author: coppice
author_rank: Super Contributor
timestamp: February 21, 2024, 04:06:34 pm
content: Quote from: pcprogrammer on February 21, 2024, 03:59:27 pmIn the UK the boiler makers quote figures in the low 90s for their condensing boilers. Perhaps the 103% to 107% is a comparison with non-condensing boilers, but that seems too low. The improvement should be well above 3%.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 21, 2024, 04:10:10 pm
content: Quote from: coppice on February 21, 2024, 04:06:34 pmThe guy who tried to persuade us to buy a oil burner stated that the condensing one, he was going to offer, had an efficiency of 107%. He clearly had no idea what he was talking about.But indeed they use it to compare non condensing with condensing types. Don't know how they get these figures, but they are useless.

author: tszaboo
author_rank: Super Contributor
timestamp: February 21, 2024, 04:33:36 pm
content: Quote from: pcprogrammer on February 21, 2024, 04:10:10 pmHis numbers might be OK, but it's calculated differently. I know how it sounds, the efficiency is still less than 100% physics wise. it was probably a condenser boiler, that includes latent heat in the calculation and that's how you reach "more than 100%".Quote from: nctnico on February 21, 2024, 12:35:33 pmI don't think it's an issue because my solar system delivered ~1KWh during the last one week daily, about 1/25th of a summer day. You certainly shouldn't size a system for that.Something else I just looked up. An Air source heatpumps uses something like 25KG of copper. So our entire copper reserves worldwide are only enough for 45 million heatpumps if we use all of it for that, which is about the number of households in Germany.Geothermal uses that as well. I guess it's also time probably to use Aluminium for these, otherwise the great plans might be in peril.

author: zilp
author_rank: Frequent Contributor
timestamp: February 21, 2024, 04:42:33 pm
content: Quote from: pcprogrammer on February 21, 2024, 04:10:10 pmSortof. AIUI that is just for historical reasons: In earlier times, it was apparently taken for granted that latent heat of water vapour was just not a thing that could be used by a heating system, and thus the value taken for 100% efficiency of a heating system was the "lower heating value", i.e., the amount of heat that could ideally be extracted from a fuel by burning it and letting the water vapour escape. And as it was thus customary to specify efficiencies relative to that number, this was continued when condensing heaters were introduced, which arguably is actually a good idea, as it allows the efficiency of condensing and non-condensing units as well as the numbers in old and new technical documents/advertisements/whatever to easily be compared. It's just that we now have fuel-burning heaters with nominal > 100% efficiency, which just feels wrong to scientifically minded people ...Well, and also, the numbers are, as all datasheet specs tend to be, taken under ideal conditions, of course. So a 107% unit probably can achieve 107% (of the "lower heating value") under some operating conditions. Probably not on average in real operating conditions, though.

author: nctnico
author_rank: Super Contributor
timestamp: February 21, 2024, 04:47:47 pm
content: Quote from: tszaboo on February 21, 2024, 04:33:36 pmYou have to size the system to deal with the maximum power output of the solar panels. Otherwise you won't get a return on investment from the solar panels. The inherent problem of solar panels is that these deliver a lot of power during a small part of the day. You need some form of storage which can deal with the peak power output.

author: tom66
author_rank: Super Contributor
timestamp: February 21, 2024, 04:54:46 pm
content: Quote from: Zero999 on February 21, 2024, 04:04:38 pmA heat pump may drop in efficiency as load increases and temperature falls, but so does a boiler. The headline efficiency of 85-90% is only achieved at the point where the return water is below 40C. Once you demand higher load from a boiler and need a flow of 70-75C, efficiency falls as far down as 70%. Meanwhile a heat pump will still be achieving a COP around 300%.Quote from: Zero999 on February 21, 2024, 04:04:38 pmEhh... maybe. But it'sa) not a net-zero compatible solution, so can't really benefit from any subsidies and can't be promoted as a sustainable alternative.b) a far more complicated solution as you need a gas turbine to drive the compressor, and appropriate maintenance for that.If it ran on synthetic gas or hydrogen maybe there'd be more interest but AFAIK those types of energy grids are decades away, if they ever happen at all.If you're thinking about hybrid heat pumps (electric heat pump plus back up boiler) they're interesting devices but I'd be worried about the longevity of a boiler component that only very infrequently runs, plus the required annual servicing costs would begin to match that of the gas usage itself.

author: zilp
author_rank: Frequent Contributor
timestamp: February 21, 2024, 05:07:28 pm
content: Quote from: tszaboo on February 21, 2024, 04:33:36 pm25e3 g * 45e6 = 1.125e12 g = 1.125 million tonshttps://copperalliance.org/sustainable-copper/about-copper/cu-demand-long-term-availability/says:Quote1.125e12 g / 870e12 g = ~ 0.0013So, I would suggest that something is wrong with your math. Annual global copper recycling would be enough 8 times over to build heat pumps at 25 kg copper each for every German household.

author: coppice
author_rank: Super Contributor
timestamp: February 21, 2024, 05:15:43 pm
content: Quote from: tszaboo on February 21, 2024, 04:33:36 pmThat can't be right. There's already more than 25 kilos of copper piping in most central heating systems.

author: nctnico
author_rank: Super Contributor
timestamp: February 21, 2024, 05:23:05 pm
content: Quote from: coppice on February 21, 2024, 05:15:43 pmCopper piping is typically not used in central heating systems. Usually the piping is from steel or plastic as copper is too expensive to use for a heating system. It could be the UK has another oddball rule which says copper piping should be used, this is not the case in the rest of the world. But I doubt copper is used in the UK as well as radiators are typically made from steel which doesn't play nice with copper in the same system (galvanic corrosion).

author: zilp
author_rank: Frequent Contributor
timestamp: February 21, 2024, 05:23:45 pm
content: Quote from: coppice on February 21, 2024, 05:15:43 pmWell, not anymore, as PEX is taking over ... but yeah, still doesn't pass a smell test, I agree.(Though, thinking about it, I am not even sure whether there still is more than 25 kg--all the under-floor heating in this house is all PEX, but the main pipes connecting the heat pump to the per-floor distribution thingies are copper, that's going to be a few kg already ...)

author: coppice
author_rank: Super Contributor
timestamp: February 21, 2024, 05:45:41 pm
content: Quote from: nctnico on February 21, 2024, 05:23:05 pmA lot of PEX pipe is used in new heating installations in the UK, but most UK homes currently have copper piping, copper and brass fittings, and pressed steel radiators. You need to put corrosion inhibitor in such a system, so electrolytic corrosion doesn't eat through the radiators. Steel piping was used a very long time ago, but was dropped in the 1950s.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 21, 2024, 06:18:23 pm
content: Quote from: zilp on February 21, 2024, 04:42:33 pmThanks for the explanation, but the guy was, in my eyes, convinced of the unit being much better than a normal one and that reductions in consumption would be superb. And that simply just is not true. For a non technical client it is a kind of false advertising, because they will believe that a liter of diesel is going to last them much longer.It depends on a lot of factors what your total efficiency is going to be, and it will never produce more then the specified 45 MJ/kg.

author: Zero999
author_rank: Super Contributor
timestamp: February 21, 2024, 06:27:05 pm
content: Quote from: tom66 on February 21, 2024, 04:54:46 pmHow does the efficiency of a gas boiler drop with temperature? The reverse is true because more heat is extracted from the water being pumped through the radiators. It's more efficient for a gas boiler to heat the water from 25°C to 75°C, than it is for it to heat from 55°C to 75°C. The opposite is true for heat pumps, which need the water to be as lower temperature as possible, hence large pipes and massive radiators, and the COP drops, with the outside temperature.I question your figure of a COP of 300%. I only use my heating when it's properly cold. It's been mild for the last week or so and my gas boiler has sat idle. 300% seems optimistic, given it'll get used when the temperature outside is close to or below freezing. Even then a COP of 300% is no good, unless the price of electricity were to fall significantly.Quoteb) No, not a gas turbine, but an ordinary, off the shelf, internal combustion engine, similar to the type used to power a small generator and will run off natural gas with only minor modifications. More complicated yes, but not so much as a gas turbine.Hydrogen or synthetic gas is only viable, if we had lots of cheap electricity, which goes back to nuclear power, although the latter can be generated through gasification of waste, similar to coal gas, which is toxic, so wouldn't be acceptable given today's health and safety standards.EDIT:Climate change politics removed.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 21, 2024, 06:34:28 pm
content: About pipes being used in central heating systems, the guys that I'm awaiting a quote from, said that they do all their work with copper pipes because there is less size reduction in the couplings.In the last house we had in the Netherlands I also did the central heating system myself and used steel pipes for the main piping to the distributors, which was still quite common at the start of this century. 28mm from the boiler down to 22 to the several distributors. From the distributors to the radiators I used 16mm pex-alu-pex since these are less permeable for air. The system worked fine, and probably still does.Here I also used pex-alu-pex or multicouche as the French say. 20mm from the tank to the distributors. Then 16mm pex-alu-pex to the radiators. For the underfloor heating I used 5 layer 16mm PE-RT.The reduction in the couplings is not a big problem. A standard radiator valve is narrower then a pex-alu-pex coupling. Sure it can create turbulence in the water and make some noise, but when it works it works.

author: zilp
author_rank: Frequent Contributor
timestamp: February 21, 2024, 06:44:27 pm
content: Quote from: Zero999 on February 21, 2024, 04:04:38 pmReally, the number to use is SCOP. COP is ambiguous and potentially means just a momentary value. And "seasonal average" is ambiguous, too, as that doesn't specify how the data points are weighted (per unit of heat output or per unit of time).350% is a reasonable value for energy-weighted efficiency (so, essentially SCOP), though, especially if it is for heating only (i.e., without hot water). While the COP certainly can drop considerably below 350% on really cold days, it can also rise considerably above it. My own heat pump has been heating at around 600% for most of February so far, for example, that pulls the average up quite a bit.Quote from: Zero999 on February 21, 2024, 04:04:38 pmThat is only true as long as the externalities are subsidized. Chances are that they will be internalized soon-ish (i.e., carbon tax or emissions trading), turning the economical solution into a stranded asset.Also, systems that burn fuels tend to have maintenance/inspection overheads that small refrigeration systems tend to not have, such as safety and emissions inspections, the need to regularly clean the burn chamber and heat exchanger both for safety and to keep the efficiency up, that sort of thing. With an air source heat pump, you might want to clean the air heat exchanger before the heating season, but that is easy to do DIY. Other than that, there isn't really any need for maintenance, just as a fridge does't require regular maintenance. Bigger systems might need inspections to make sure that the refrigerant isn't leaking, especially if it's high-GWP refrigerant, or a flamable refrigerant indoors.

author: soldar
author_rank: Super Contributor
timestamp: February 21, 2024, 06:55:43 pm
content: Quote from: pcprogrammer on February 21, 2024, 04:10:10 pmWhen i was a kid they advertised a clothes detergent that washed "whiter than white". I'm still scratching my head over that one. I think it may have caused irreparable damage to my mind.

author: Zero999
author_rank: Super Contributor
timestamp: February 21, 2024, 07:02:15 pm
content: Quote from: zilp on February 21, 2024, 06:44:27 pmI don't use hot water.I haven't really run my gas boiler much this February, perhaps the odd day or so. It ran quite a bit for a couple of weeks in mid-January and at the start of December, but that's it.QuoteNot true. My gas boiler only needs to be serviced every few years. The last time was about four years ago and cost £60, which is a tiny fraction of my energy bill.EDIT:Climate change politics removed.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 21, 2024, 07:18:13 pm
content: Quote from: Zero999 on February 21, 2024, 07:02:15 pmHow do you do the dishesMust be cold in the shower.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 21, 2024, 07:20:23 pm
content: Quote from: Someone on February 20, 2024, 11:19:17 pmThough, recharging is absolutely utterly trivial. For some weird reason, it is usually not being done; people invest 20-25k€ on a system which misses a simple opportunity which costs a few hundred extra. I think it's chicken and egg problem; people don't understand the need, thus no one asks for it, thus it's not provided, thus it's weird custom work and therefore expensive if possible at all.As long as the drill hole is correctly dimensioned, it all works out. But underdimensioned systems are surprisingly common here, like you pay 25k€ for the expensive heatpump itself + to get the boring equipment at your place and drill 155 meters as miscalculated by sales people trying to pinch the last penny, when you could pay maybe 500€ extra for 20-30 meters deeper. And/or 500€ extra for a turnover valve plus something which resembles car radiator, for summertime charging.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 21, 2024, 07:27:29 pm
content: Quote from: tom66 on February 21, 2024, 03:47:10 pmAnd hybrid combination of which, such that gas is used when very cold, and electricity used when COP is good (and, lower rates available - I mean, you guysdohavesomesort of variable pricing if not hourly spot prices, right?) - will be significantly cheaper than either of the two separately. Just running cost, ignoring the investment, of course. If you have a working gas boiler then quite obviously given such absurdly low prices it makes little sense to do any modifications.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 21, 2024, 07:34:58 pm
content: Quote from: pcprogrammer on February 21, 2024, 03:59:27 pmThey are not all that expensive, but because they are expected to bring large savings to the customer, larger profit margin can be explained.Never heard about De Dietrich. It's probably just some label on some Asian product, like 90% of heatpump brands (including "German" brands like Bosch). Many heatpumps are label over label over label.I simply chose a cheap air-to-water heatpump (made by the world's second largest heatpump manufacturer, pure Chinesium at its best) which still has labeling, but the label of (Swedish) EnergySave costs only maybe +100%, not +300% like some other labels like Nibe.But ground source units are manufactured in smaller numbers so they are more expensive for what you get. Internally they are even simpler, and fundamentally cheaper to manufacture than air-to-water units, but you pay premium for worse economics of scale, plus extra for higher expected savings (status of a "better" system).

author: m k
author_rank: Super Contributor
timestamp: February 21, 2024, 07:36:53 pm
content: Quote from: pcprogrammer on February 21, 2024, 01:21:48 pmMaybe one thing, for the blue moon.Do not use RS-485 for long distances, put a converter near the pump, or an isolator.Yes, it's made for that, but you do not want that the pump side fails.With luck you have a machine with multiple circuit boards, but it's a monoblock.With bad luck there's only one PCB and the driver is integrated to MCU.

author: Zero999
author_rank: Super Contributor
timestamp: February 21, 2024, 07:46:11 pm
content: Quote from: Siwastaja on February 21, 2024, 07:27:29 pmI believe the silly subsidies are only granted, if you get rid of the existing gas boiler: no hybrid allowed. That's why I'll keep my current system at the moment. If it does break down, I might consider a gas powered heat pump, or at most a heat pump ready system. The problem is, it would involve new, bigger radiators and pipes which cost money to install. Fortunately my house has a drywall cavity so it shouldn't involve digging the floor up.Quote from: pcprogrammer on February 21, 2024, 07:18:13 pmThe detergent I use works really well with cold water. If it's really greasy, I'll boil a kettle, or put the pan on the gas stove, but it's normally not needed and is the exception, rather than the norm.QuoteI almost always shower cold. I cycle home from work at a decent pace and by the time I'm back I'm dripping with sweat, so the last thing I want is a hot shower. The exception is when I'm off sick and even then, I just set it to body temperature. I usually wash my hands with cold as well, because hot water dries my skin.Quote from: pcprogrammer on February 21, 2024, 01:21:48 pmThat's true. I was thinking of a fun project. I doubt it's practical for you.QuoteAre you sure it's a good idea to get something which isn't very well documented? Going by what you've said, that company could be a pain to deal with.

author: zilp
author_rank: Frequent Contributor
timestamp: February 21, 2024, 07:51:07 pm
content: Quote from: Zero999 on February 21, 2024, 06:27:05 pmFor one, your average condensing boiler uses outdoor air as the oxygen source. Colder outdoor air requires more energy to heat up to the target temperature. At the same time, colder outdoor temperatures require a higher water temperature to keep the house warm, thus the exhaust gets warmer.And while it is correct that heating water from 25°C to 75°C is more efficient than heating water from 55°C to 75°C, that is not how a modern, well-designed and properly configured gas-fired heating system operates. If we assume a constant flow of water, the variable to change the heating power delivered to the house is the temperature spread between source and return. So, in order to adapt heat delivery to colder outdoor temperatures, the boiler will provide hotter water, which increases heat dissipation by radiators or under-floor heating, ideally keeping the return temperature constant--in practice, the return temperature will rise, too (the ideal case would require excessively large radiators that would allow the water to cool down to room temperature). So, an efficient modern gas heating system heats hotter input water to hotter output water when it is colder outside, not colder water to equally hot water, and thus get less efficient at colder outdoor temperatures.Quote from: Zero999 on February 21, 2024, 06:27:05 pmThat suggests that either your house is very well insulated (in which case, heat pumps, somewhat unintuitively, indeed often are less advantageous than in less well insulated houses), or you have significant other waste heat sources that keep your house warm (which might be at significant energy costs if it is from electrical devices that could be swapped for more efficient versions), or you like it cool indoors (in which case, you could expect a higher COP from a heat pump).I am assuming that "mild" is around 10°C? That's what we've had here, with the ~ 600% COP I mentioned above.Quote from: Zero999 on February 21, 2024, 06:27:05 pmThat isn't really true. While it is true that a lot of bullshit is marketed as "net zero" (i.e., you burn coal and pay us to not cut down this forest that noone intended to cut down anyway ... and thus you burning coal is now net zero!11), actual zero emissions isn't really possible, and thus remaining emissions will have to be compensated, in a real way. Also depends on how exactly you do the accounting. For example, if you grow wheat, you get straw. Unless you store that straw in dry conditions forever, it will decompose one way or another and thus emit CO2. But as that carbon was taken from the atmosphere just a few months prior, that is net zero in a perfectly sensible way. And if you do things right, you can even convert some of that straw into longer-lived carbon-storing molecules, such as soil, effectively reducing the CO2 content of the atmosphere. It's just that that isn't something that we can reasonably do at a scale that would allow us to continue burning fossil fuels as before, it really is only one minor thing that we can do to compensate emissions that absolutely can not be avoided.Quote from: Zero999 on February 21, 2024, 06:27:05 pmHow did you calculate the future costs of running a gas boiler? Mind you that chances are that you'll have to pay for the damages that your CO2 emissions cause at some point.Quote from: Zero999 on February 21, 2024, 06:27:05 pmI mean, I guess we are getting really off topic here, but ... gold is not a productive asset and therefore not really an investment. It's a speculation vehicle at best.Quote from: Zero999 on February 21, 2024, 06:27:05 pmBut those only have an efficiency of ~ 30%, I think?! Combine that with a COP of 300% and you are at an efficiency of 90%. Of coure, you can then also use the waste heat, but for one that again requires an exhaust heat exchanger (that needs to be cleaned), and also, the overall efficiency still would seem like barely worth the complexity and presumably system cost!?

author: m k
author_rank: Super Contributor
timestamp: February 21, 2024, 08:01:36 pm
content: I also usually was my hands with cold water.It's a physical thing.Hot water is so far it hardly reaches the tap in time.

author: zilp
author_rank: Frequent Contributor
timestamp: February 21, 2024, 08:27:15 pm
content: Quote from: Zero999 on February 21, 2024, 07:02:15 pmThen 350% is perfectly reasonable average SCOP. Hot water requires high temperatures and thus tends to have a low COP, thus drawing down the combined average.Quote from: Zero999 on February 21, 2024, 07:02:15 pmWell, the interesting question would be: At what indoor and outdoor temperatures, and how much heat do you get from other sources?Quote from: Zero999 on February 21, 2024, 07:02:15 pmThat seems contradictory? If nuclear is supposedly cheap electricity, then why would the government have to invest in it? Especially when increasing demand is expected with more heat pumps being deployed, why would it need the government to provide the investment for that cheap electricity?And while I am not familiar with the subsidies currently available in the UK for heat pumps and thus have no idea how sensible those particular programs are, it is way too simplistic to say hat subsidies are necessarily "a false economy". While subsidies of course can hide market failures and all that, markets also have a lot of threshold effects and coordination problems that can be solved with (limited time!) subsidies, and I can see quite a few reasons why that might apply for heat pumps (essentially: Creating a reliable sustained demand that incentivizes manufacturers to build heat pump factories and installers to learn how to install them, which in the mid term should increase supply and thus decrease prices).And also, arguably, paying people to install heat pumps isn't even a subsidy, as you could also understand it to be, at least in part, paying them to keep CO2 out of the atmosphere, thus compensating them for the increased cost of doing so. After all, keeping CO2 out of the atmosphere benefits all taxpayers, not just those who install heat pumps. In fact, it is overwhelmingly to the benefit of other people.Quote from: Zero999 on February 21, 2024, 07:02:15 pmWell, that's not that bad. Last place I lived with gas heating required inspection by the chimney sweep every two years (~ 120 EUR) and cleaning/inspection by the installer once per year (~ 100 EUR). The former certainly is in part just a result of regulation in Germany, but as for the latter: Do you just use your boiler so little that it stays clean/efficient that long?

author: Someone
author_rank: Super Contributor
timestamp: February 21, 2024, 08:31:19 pm
content: Quote from: Zero999 on February 21, 2024, 11:48:16 amFFS, provide in context and relevant data yet the majority that comes back is extraneous dismissals?That link of the source data has: petrol (gas), electricity, and.... natural gasThe provided plot has electricity and natural gas.Or is UK petrol 10c/kWh ?Want to talk about these things, you'd better get your facts barely tested first.

author: Someone
author_rank: Super Contributor
timestamp: February 21, 2024, 08:33:57 pm
content: Quote from: nctnico on February 21, 2024, 12:35:33 pmAgain with your pushing of solutions and completely ignoring/side stepping the practical ones (pretending like no other options exist).Oversize the solar array, then it will produce enough energy in winter.Sure not everyone has the physical space for that, but few have the physical space for ground source thermal storage/dissipation.

author: Zero999
author_rank: Super Contributor
timestamp: February 21, 2024, 08:34:10 pm
content: Quote from: zilp on February 21, 2024, 07:51:07 pmBoth are true. I have my thermostat set to 15°C and my house is very well insulated.QuoteYes and my boiler just sits there, so that's irrelevant. It'll probably run a bit at the end of the week when the temperature drops to 5°C.QuoteOne cannot predict the future. I'm open minded about the possibility of changing, but will stick to what's cheapest for now. I'm willing to listen to rational arguments, but don't take kindly to propaganda and zealotry. I'm well and truly fed up with it from the mainstream media.QuoteIrrelevant, since most of the emissions are from other countries who will not cut them.QuoteGold is a precious metal and is limited in supply, so will only become more valuable over time. The only risk is someone discovers a way to make it cheaply. Given this is highly unlikely, it's certainly a better investment, than an electric heat pump!QuoteI thought you said a COP of 600%? Make your mind up!Natural gas is a clean fuel, so the exhaust won't be any more dirty than my boiler.Assuming an electric heat pump would give a COP of 300%, a gas one would give a COP of 160% and given gas costs a quarter of the price, it would pay for itself within a few years. An electric heat pump would just cost me more than my current system, both in terms of upfront and running costs. I'm hardly unique. Many others in the UK have found electric heat pumps to be uneconomical here. I'm not against the idea. It just doesn't make any sense, in my situation.EDIT:Climate change politics removed.

author: Zero999
author_rank: Super Contributor
timestamp: February 21, 2024, 08:39:28 pm
content: Quote from: Someone on February 21, 2024, 08:33:57 pmYou must be joking about over sizing the array for winter. That might work in Australia but would require an huge area in Northern Europe, when there's less than 8 hours' of weak, overcast daylight on the shortest day of the year.Quote from: Someone on February 21, 2024, 08:31:19 pmOkay, fair point. I admit, I just looked at the map at the top and didn't read down the page.

author: zilp
author_rank: Frequent Contributor
timestamp: February 21, 2024, 08:42:24 pm
content: Quote from: m k on February 21, 2024, 07:36:53 pmOften, such a bus in a heating system is intended for the connection to additional components like room thermostats or external mixers or secondary heat sources or what have you, so, while the protocol/data fields might be proprietary, the interface is absolutely expected to be connected outside the heater and thus will usually not be just a bunch of GPIO pins on a connector. Also, the connectors tend to be sturdy stuff (like pluggable 1.5 mm² screw terminals), not pin headers or sume such.Of course, it's still a good idea to put an isolator between it and any computer you connect to it ...

author: Someone
author_rank: Super Contributor
timestamp: February 21, 2024, 08:45:49 pm
content: Quote from: coppice on February 21, 2024, 02:10:54 pmSo provide some more appropriate data yourself?People here are talking about what they pay for energy in its different forms, the relative costs of their energy choices are KEY to this discussion. Yet both sides of the extreme are talking like their situation is completely universal and applies to everyone else. They need to be clearly stating that it is only applicable to their unusual locality and not a general case.I remember when gas was a 1:4 or 1:5 ratio, but that's not sustainable economically (rationally). Given the uses of gas a realistic price ratio is heading somewhere closer to 1:2, many countries are already there and betting on cheap gas being either:a) available in other locations, orb) continuing the large price ratio into the futureare both unrealistic. But do just argue about any data only being somme single point in time. It's on you to add what you think is constructive rather than trying to claim there is nothing to be gained from the data I have shared.Plenty of the worlds electricity is tied to gas prices:https://data.worldbank.org/indicator/EG.ELC.NGAS.ZSGiven the electricity markets and their bidding methods, the most expensive generators are setting the price, often natural gas.

author: Zero999
author_rank: Super Contributor
timestamp: February 21, 2024, 08:49:56 pm
content: Quote from: zilp on February 21, 2024, 08:27:15 pmIf the goal is to reduce carbon emissions, then investing in nuclear power, so we have cheap electricity, is a no-brainer. Nuclear plants have a high upfront cost, which few private investors are wiling to pay, so it make more sense for the government to invest in it, rather than wasting money on other green schemes such as heat pumps and banning internal combustion engine vehicles. Given cheap, clean, electricity, people will voluntarily switch to heat pumps and electric cars, without subsidies or banning anything. It will also boost the economy, in the form of reduced energy costs to businesses. Nuclear power will see a return on investment, in the long term.

author: Someone
author_rank: Super Contributor
timestamp: February 21, 2024, 08:51:14 pm
content: Quote from: Zero999 on February 21, 2024, 04:04:38 pmWe've been here before again and again.You can choose to make that analysis on the worst case. But it doesn't make sense unless you have zero cost for your plant, and multiple heating systems installed. That makes sense to almost no-one.Realistically most people invest/gamble on a single heating source and use the same one all year round. So their fuel costs for the year at SCOP are the correct metric, and depreciation of the plant over its expected life.

author: Someone
author_rank: Super Contributor
timestamp: February 21, 2024, 08:57:24 pm
content: Quote from: soldar on February 21, 2024, 06:55:43 pmThey can be true, many clothes washing detergents/powders add mixtures of fluorescent pigments/dyes which absorb UV and return "white". End result being the clothes washed in that load will be brighter (under sunlight). Same trick is done with expensive paper stock.Similar sleights of hand are commonplace in discussion of heating/heat-pumps.

author: coppice
author_rank: Super Contributor
timestamp: February 21, 2024, 09:04:23 pm
content: Quote from: Someone on February 21, 2024, 08:45:49 pmFrom my bill from my bill for Dec 2019, just before things started to go weird. Gas was 3.10p per kWh. Electricity was 14.35p per kWh. Those prices are from a single integrated energy bill. That's about in line with the actual cost of provision. Have you looked at how much of your electricity bill goes to pay for the fuel? UK bills used to have the fuel component broken out from the cost of running the grid. The fuel wasn't that big a part.

author: Someone
author_rank: Super Contributor
timestamp: February 21, 2024, 09:07:16 pm
content: Quote from: Siwastaja on February 21, 2024, 07:20:23 pmAs discussed in that other linked thread. Ground source works well if you have sole access to the resourceordon't care about 20+ years into the future.It's that 100mW/m2 replacement rate thing, which happens to be close to 1kWh per year per m2 of land area. For the OP who's wanting 16500kWh annually and very little air conditioning, that's a massive sized block needed to be sustainable! Or they should factor in some energy for replenishing the ground source which is additional expense again.

author: Someone
author_rank: Super Contributor
timestamp: February 21, 2024, 09:10:30 pm
content: Quote from: coppice on February 21, 2024, 09:04:23 pmLearn how wholesale electricity is priced. They don't run fixed margins or simple input costings.Also, you can keep pointing to UK examples. That's my point that I keep pushing. Hold onto them for dear life and enjoy that distorted market. It won't last, and it's just a UK thing. The rest of the world is not getting those huge price differentials.

author: coppice
author_rank: Super Contributor
timestamp: February 21, 2024, 09:11:23 pm
content: Quote from: Someone on February 21, 2024, 09:07:16 pmThe replacement rate is all over the place, depending on the kind of land you are on. Its seldom very high, but trying to use a single figure doesn't make a lot of sense.

author: Someone
author_rank: Super Contributor
timestamp: February 21, 2024, 09:17:37 pm
content: Quote from: coppice on February 21, 2024, 09:11:23 pmIt makes a lot of sense when that figure is applicable (within +/-50%) to the vast majority of people). Well done distracting people on a small discrepancy when the discussion is about people pullingseveral orders of magnitudemore than the sustainable rates.but but but something is a factor of 2 out....don't mean squat when the problem is a factor of 1000

author: coppice
author_rank: Super Contributor
timestamp: February 21, 2024, 09:19:46 pm
content: Quote from: Someone on February 21, 2024, 08:45:49 pmI point to UK examples as I know how things have been here for half a century, so I have a long term view. Since a pipeline network brought natural gas to our homes in the late 1960s it has been a small fraction of the cost of coal or electric heating, and considerably cheaper than oil, which people in the countryside still have to use.

author: coppice
author_rank: Super Contributor
timestamp: February 21, 2024, 09:21:09 pm
content: Quote from: Someone on February 21, 2024, 09:17:37 pmYou know some people have water flows through the soil below their homes that gives them a rapid replacement of harvested energy. It really is a wide range.

author: Someone
author_rank: Super Contributor
timestamp: February 21, 2024, 09:31:22 pm
content: Quote from: coppice on February 21, 2024, 09:21:09 pmAnd like your unicorn pricing for gas in the UK, that's the unusual/exceptional case.Why keep coming in and arguing I cant discuss typical/average figures? (as I'm happy to explain and frame them as such).You're being misleading and adding noise by jumping to the extremes as some alleged examples, but without actually saying that they are extremely specific/unusual. Things need to be explained in context, not just short "look at me" technically true by omission rubbish.Why keep coming back and trying to cut down the typical/reasonable/supported positions? It's trivial to point out you're just using extreme cases.

author: zilp
author_rank: Frequent Contributor
timestamp: February 21, 2024, 09:57:05 pm
content: Quote from: Zero999 on February 21, 2024, 08:34:10 pmWhy not?Quote from: Zero999 on February 21, 2024, 08:34:10 pmThat sounds like you need a border adjustment tax?Quote from: Zero999 on February 21, 2024, 08:34:10 pmWhy not?Quote from: Zero999 on February 21, 2024, 08:34:10 pmDo I smell propaganda at work?Quote from: Zero999 on February 21, 2024, 08:34:10 pmHow is that a relevant response? If you have to pay for the damages, that doesn't get cheaper even if it is true that most of the emissions are from other countries who will not cut them, does it?Quote from: Zero999 on February 21, 2024, 08:34:10 pmNo, that doesn't follow. And really, I smell propaganda that has convinced you of such nonsense in order to sell you gold, using your rudimentary understandig of economics and your distrust of "main stream whatever" to turn you into a mark for someone's scam.Price results from supply *and* demand. Limited supply with decreasing demand still leads to decreasing prices. As the majority of gold demand is from speculators, there is no fundamental reason why demand couldn't decrease (as opposed to technical uses, say, where the practical value of the products that contain gold and where gold is hard to substitute drive the demand). Really, what keeps the value of gold up is exactly such marketing campaigns that mislead people who lack deeper economical understanding into "investing" in it, because that is what generates the demand.If you buy gold, that's a bet on other people buying gold, and them doing so at a higher rate than gold is supplied to the market, so that you can later sell it to them. That's it.Which is in contrast to investment, i.e., putting your financial resources into things that produce other things of value. Like, if you buy a (share of a) company that owns a machine that makes bread, where the machine making bread produces value (because of the value of bread for people's survival that people are willing to pay for) that you get a share of.Quote from: Zero999 on February 21, 2024, 08:34:10 pmWell, no. It certainly has a different risk profile, but it is in no way obvious that putting your money into gold would have a higher return than putting it into a heat pump over the lifetime of the heat pump. Though maybe things are different for you personally, given that you seem to use very little heating anyway. But then again, possibly a simple, relatively low-power air to air heat pump could actually work for you, and those can often be had relatively cheaply.Quote from: Zero999 on February 21, 2024, 08:34:10 pmThere is no need to make up my mind, you just have to pay attention.I am *currently* (as in: most of February so far) heating with a COP of around 600%. As in: Right now, my heat pump draws 476 W electric (pumps and everything included) and outputs 2786 W of heat, so 2786 W / 476 W = 585 % COP.Which I mentioned above to explain why an average of 350% is reasonable, even though the COP can be lower during really cold days.To compare heating systems, you obviously have to use annual averages, and that certainly is not 600%.And also, I used the 300% because that was the number that you used in the post that I was replying to.Quote from: Zero999 on February 21, 2024, 08:34:10 pmWell, it is clean in comparison to other fuels. But it is not clean as in "doesn't leave any residue". Whether it would be dirtier than your boiler isn't really that easy to say, as the dirt that results from the combustion really depends on the conditions.Quote from: Zero999 on February 21, 2024, 08:34:10 pmHow did you get to that number?Quote from: Zero999 on February 21, 2024, 08:34:10 pmWhat price are you assuming for a gas-driven heat pump, and how did you arrive at it?I have no idea what they cost, but I would expect them to be even more expensive than electrically driven ones as they are more complex to build (combustion engine vs. electric motor) and more difficult to install (need a gas line i addition to electricity and potentially refrigerant lines)!?

author: coppice
author_rank: Super Contributor
timestamp: February 21, 2024, 09:58:12 pm
content: Quote from: Someone on February 21, 2024, 09:31:22 pmIts not that rare. Certainly ground sourcing has problems for most people, but there is a significant pool of people on suitable for whom ground sourcing seems like a solid long term solution. For keeping a home comfortable there is no one size fits all solution.So, what are the kWh prices from your energy bills pre-COVID and Ukraine war? Have the long term trends for their ratio been steady? When the UK started running low on gas from the North Sea a lot of us assumed heating costs would rapidly rise, but they didn't until the recent troubles. I wouldn't call prices sustained for decades as unicorn prices. Your point about wholesale electricity prices misses the point. Those are the prices the grid pays the producers. The prices the grid charges end users have to add a lot of the grid costs onto the wholesale prices, and they are not small.

author: themadhippy
author_rank: Super Contributor
timestamp: February 21, 2024, 10:05:27 pm
content: QuoteArent those cost what the standing charge is meant to cover

author: coppice
author_rank: Super Contributor
timestamp: February 21, 2024, 10:21:40 pm
content: Quote from: themadhippy on February 21, 2024, 10:05:27 pmThat is a contribution to grid maintenance when you are connected but not consuming (i.e. nobody at home). Its not the full grid cost. The huge costs of maintaining a grid are what made the people in the 1950s who said cheap sources (mostly nuclear) could make electricity too cheap to bother metering so obviously clueless.

author: Someone
author_rank: Super Contributor
timestamp: February 21, 2024, 10:27:00 pm
content: Quote from: coppice on February 21, 2024, 09:58:12 pmThis is a worldwide forum, with an OP asking about merits on mainland Europe. So yes, UK pricing is a minority viewpoint/effect, and being a massive outlier in pricing while being a small market make that a unicorn. I put up the evidence and links to source material for those claims.Quote from: coppice on February 21, 2024, 09:58:12 pmYou said fuel prices don't make a substantial dent in your overall energy bill.a) that's for fuel in this corner case of the UK marketb) that's averaged across the year and generation mix (unstated)c) how the fuel cost contributes to the consumer electricity price is unlikely to add only to that "portion" of the bill as presented to youI was commenting on your overly simplistic view of energy pricing, which you're doubling down on. Keep talking about the UK as if its some universal truth applicable to the rest of the world and you'll keep getting the same response.....

author: Someone
author_rank: Super Contributor
timestamp: February 21, 2024, 10:30:43 pm
content: Quote from: coppice on February 21, 2024, 09:58:12 pmSays youcitation required.Or are you moving the goalposts? From the thermal resource available to people is generally much higher than 100mW/m2, to that doesn't actually matter because most people will recharge the resource?You're just throwing out argument for noise at this point when you cant even be clear what it is you are claiming.

author: tszaboo
author_rank: Super Contributor
timestamp: February 21, 2024, 10:34:44 pm
content: Quote from: coppice on February 21, 2024, 05:15:43 pmI think it's just the outside heat exchanger that has that much copper. Anyway, double checking it my math is off by a magnitude or so. It didn't make sense after reading it again.Quote from: Someone on February 21, 2024, 08:33:57 pmAlmost nobody has place for that here. I have a system that covers my yearly electricity consumption, in fact makes an extra MWh. And I needed 5 GJ heat this december, which is 1400KWh, while my solar made 52KWh, which is a factor of 27. Even with SCOP of 5, it's just not going to be worth it to install 6x the solar on my roof, no space, no money for it.

author: zilp
author_rank: Frequent Contributor
timestamp: February 21, 2024, 10:38:49 pm
content: Quote from: Zero999 on February 21, 2024, 08:49:56 pmHu? Where did you get the idea that few private investors are willing to pay high upfront costs with almost guaranteed returns?! I mean, unless you mean "few" as in "most individual people don't have the money to pay for a nuclear power plant"?! I mean, BlackRock have 9 trillion USD of assets under management ... they certainly could find a bunch of people among their clients who would have the cash to build a nuclear power plant and would be willing to do so for reliable returns!? Sounds almost ideal for pension funds! And they obviously aren't the only large asset managers out there.My best guess is that what you've heard is that few private investors are willing to fund high upfront costswith significant risks. Like, funding billions for medical research where there is a significant chance that nothing comes of it. Which is true. But that isbecause of the risk, not because of the high costs. And if there is significant risk, then that is exactly the contradiction that I was talking about: How can a nuclear power plant be both a reliable cheap source of electricity (which thus would have reliable long-term returns, if you own the power plant that can produce power cheaper than everyone else) and at the same time a high-risk investment that would need the government to step up?Quote from: Zero999 on February 21, 2024, 08:49:56 pmWhy do you think that that is wasting money?Quote from: Zero999 on February 21, 2024, 08:49:56 pmWell, that much is obvious, yeah.Quote from: Zero999 on February 21, 2024, 08:49:56 pmThat part though ... your arguments certainly don't support that conclusion.

author: tom66
author_rank: Super Contributor
timestamp: February 21, 2024, 11:12:51 pm
content: Quote from: Zero999 on February 21, 2024, 06:27:05 pmUnfortunately, it does. Because condensing boilers don't condense when the return temperature is above 45-50C (roughly). Typically the radiator loop on your system might lose 20-25C between flow and return, but if your radiators are sized so that it can only be properly heated when the flow output temperature is >60C then it will suffer from reduced efficiency in cold weather. This is currently the case for our house, and it's sadly very common as heating engineers aren't physicists, they just know that they need so many kW per m^2 so install the smallest radiators they can get away with.When a boiler doesn't condense, the exhaust ends up with plenty of waste heat in it, which isn't heating your property. Combi boilers also do not condense when providing hot water, as there is no return path.No such issue occurs for a boiler that is non-condensing, those are rare (especially today) and just generally have all-round bad efficiency.Quote from: Zero999 on February 21, 2024, 06:27:05 pmA property in the UK will only be approved for the grant when a COP of at least 280% is achieved. Octopus only install systems >330% COP. One can surmise from this is most systems installed under the MCS scheme will have a COP of 300% or above. Octopus are the largest installer of these systems.You are not the only user of heating systems so I couldn't comment on whether your scenario is going to achieve worse efficiency or not... but it's probably not relevant to the overall economics of heat pumps, most around here use their heating for at least 4-5 months of the year. It's pretty easy to see the boiler vents on a cold day after all.

author: Someone
author_rank: Super Contributor
timestamp: February 22, 2024, 02:16:37 am
content: Quote from: tszaboo on February 21, 2024, 10:34:44 pmWhich you know... I said (and you quoted). The size of that setup is comparable to the sustainable footprint ground source heating in those cold places where little to no air-conditioning is needed (and solar production falls way off in winter).Why go straight to extremes with a pure solar setup? its a convenient strawman? Energy supply is almost always cheapest as a mix of things.Sizing solar arrays to the inverter or export limit is old thinking. Panels are cheap and adding more capacity (vertical for winter production for example) can be cost effective for many.Also to be pedantic you don't need 5 GJ of energy for heating, you want 5 GJ of energy for heating. That's a choice and how you supply it is up to you (and you can pay for it).

author: Miyuki
author_rank: Frequent Contributor
timestamp: February 22, 2024, 06:26:25 am
content: Quote from: zilp on February 21, 2024, 10:38:49 pmNuclear power has a big problem, you have those same crazy dudes glued to the road also protesting against nuclear.And as there is no economy of scale nowadays, the cost is enormous.Current builds will be profitable in 30-40 year horizont (if there won't be any problems). So no investor will go into this because it is beyond their lifetime and when you have investment opportunities with orders of magnitude higher returns. And even after that 30-40 years, those profits are not that great.And even governments are reluctant because it is controversial, because of those factors.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 22, 2024, 07:59:06 am
content: Quote from: Siwastaja on February 21, 2024, 07:34:58 pmDe Dietrich is a very old French brand. At some point it joined ventured with Remeha a Dutch brand. I have no idea where the pump offered is fabricated. The reviews seem to be good and put it up at the top with Daikin and Mitsubishi.Quote from: m k on February 21, 2024, 07:36:53 pmMy system has provisions for UART with optical isolation. This coupling will be very close to the pump unit. For what I found on it, it is bog standard RS485 and used to connect their brand thermostats. It will be protected against things like lightning to some extend.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 22, 2024, 08:06:37 am
content: Quote from: Zero999 on February 21, 2024, 07:46:11 pmI'm not afraid of a bit of research. If needed reverse engineering is a way to go. The whole thing will become a big experiment to reach a solid and economical solution.

author: Zarhi
author_rank: Contributor
timestamp: February 22, 2024, 08:53:28 am
content: That's is situation with air source heat pumps from this morning:Outside temp 2°C, humidity about 60%, clear sky, no rain, no clouds, no fog.Pictures taken 3-4 minutes after defrost cycle completion.Anyway in the morning inside temperatures was:First floor: bedroom - set 22°C, actual 22°C, living room set 24°C, actual 25°C.Second floor: two bedrooms - set 22°C, actual 23°C.Last 10 hours electricity consumption: 12kWh

author: tszaboo
author_rank: Super Contributor
timestamp: February 22, 2024, 09:22:38 am
content: Quote from: Someone on February 22, 2024, 02:16:37 amI'm a bit confused, in one comment you say we should oversize solar system to cover winter energy needs. When I show you it's not practical, you say that's not what you said. So then what is your suggestion?And yes, I do need 5GJ for a winter to be bearable in my home, dropping temperatures lower than most people keep here would be a respiratory hazard. To be pedantic, I don't really care about global warming and polar bears, if I cannot keep temperatures at home high enough to live a quality life. And if the government has a problem with this, we'll overthrow the government and bring out the guillotines for good measure.

author: nctnico
author_rank: Super Contributor
timestamp: February 22, 2024, 09:58:24 am
content: Quote from: pcprogrammer on February 22, 2024, 08:06:37 amI know this is a great project but try to keep in mind that a generic heating service person needs to be able to fix your heating system. You may go away for a while or become incapacitated. Then your wife is left in a cold home without warm water if your self-build heating system breaks. Most likely a heating service person will either go away or tear your system down and replace it with something the person knows how to deal with (followed by a large invoice).

author: m k
author_rank: Super Contributor
timestamp: February 22, 2024, 10:35:57 am
content: Quote from: pcprogrammer on February 22, 2024, 08:06:37 amI think the only big issue you finally have is how successfully the pump is positioned.But how big is big is questionable, obviously after the pump itself is generally fine.Maybe you add a battery backed circulation pump no matter what.Maybe you must later add some acoustic insulators, but so be it then, even if you must dig under the foundation, it's actually not very big qube.(how high can engine hoist lift)What comes to generic heating service persons around here, more experienced ones are many times very aware of many kind of specialities.Since these things are generally pretty fine over longer periods of times these service fellas must have a wide customer base.Around here it can include stores, dairy farms, meat packing places and so on, plus considerably old water circulations around different generations of machines.BTW,that earlier mentioned cold water is actually not very cold.It's from pipes that are around a room temperature and a tap lever is usually lifted straight up, so somewhere around the middle.Winter stream water is cold, even as cold as tap can give is not really cold, winter times it's probably close to 6C.People who swim in ice hole would probably argue against the whole concept of cold water.BTW2,I had to drop HVAC target temp, the area was closing to 23C and ask was 19C.The machine has been a bit eager from the beginning.It's Panasonic E12 series scroll and my educated guess is that it's internal curves are too low for our temp ranges.Maybe it's because of missing liquid, but if outdoor temps are skyrocketing or dropping equally it sometimes goes bonkers.Then removing mains for a moment will do the trick, luckily it's indoor unit fed wall plug thing that actually has that plug.

author: zilp
author_rank: Frequent Contributor
timestamp: February 22, 2024, 12:32:42 pm
content: Quote from: tszaboo on February 22, 2024, 09:22:38 amYou are aware that climate change is about your survival, not about the survival of polar bears, right?I mean, the expectation of having a reasonably heated home is perfectly reasonable, obviously. But then, exactly noone is suggesting anything otherwise, so your whole statement is pretty pointless even in that regard.

author: NiHaoMike
author_rank: Super Contributor
timestamp: February 22, 2024, 01:42:14 pm
content: Quote from: zilp on February 20, 2024, 12:26:55 pmHas absorption heat pump technology improved substantially? Last I checked, it's about as efficient as running an electric heat pump from a gas generator. Might as well get a CHP generator and an electric heat pump to get more flexibility.But as larger systems are more economical, it would work out better to split it up. Have some households with electric heat pumps and some with CHP generators. In colder weather, the CHP generators run more which nicely matches up to the heat pumps also running more.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 22, 2024, 07:34:05 pm
content: Quote from: nctnico on February 22, 2024, 09:58:24 amThis sort of stuff is usually easy to solve with some kind of manual bypass switch. Or short instructions e.g. "go to menu X and change external control to internal control". Something worth thinking about, yes.

author: zilp
author_rank: Frequent Contributor
timestamp: February 22, 2024, 07:44:02 pm
content: Quote from: Miyuki on February 22, 2024, 06:26:25 amThat is not how investment works.For one, there are plenty of investors where 30-40 years is not in any way beyond their lifetime. Think insurance companies, pension funds, endowments, that sort of thing. Plenty of investors who wouldn't care if they couldn't liquidate some position for half a century, as long as the returns are worth it.But also, that is what the secondary securities markets are for. If the profits are as certain as has been suggested, then you can just hold the shares or bonds and then sell them after 30 years or whatever for the time value of the future profits, thus getting your part of the profits before they have been realized.Quote from: Miyuki on February 22, 2024, 06:26:25 amAnd that is the point. It's actually risky. There is absolutely no guarantee that the electricity would be competitive with other sources, and quite a few reasons to think that it wouldn't. And if it isn't, then throwing a pile of tax money at it is just a waste of money. And that especially so given that even if we decided to build a ton of nuclear power plants, they wouldn't be online for at least another 10 years. A lot of solar and wind capacity can be built in ten years, and any generator that is completed pretty much immediately starts saving CO2, rather than in ten years. And also, wind and solar are proven technologies with economies of scale, where the time to compltion is very reliably predictable, as far as the technical side is concerned.

author: Zero999
author_rank: Super Contributor
timestamp: February 22, 2024, 09:14:08 pm
content: Quote from: tom66 on February 21, 2024, 11:12:51 pmOkay, I accept those figures, but they still don't make economic sense for me. It just doesn't add up at the moment.Quote from: Miyuki on February 22, 2024, 06:26:25 amThere are also smaller nuclear reactors which are cheaper to build. I believe Rolls Royce are currently developing modular units.

author: tom66
author_rank: Super Contributor
timestamp: February 22, 2024, 09:16:04 pm
content: Quote from: zilp on February 22, 2024, 07:44:02 pmIndeed, only 10 years since the UK paid off its last undated bonds, some of which go back to the 1850s.https://www.gov.uk/government/news/repayment-of-26-billion-historical-debt-to-be-completed-by-governmentThere are public-private financing schemes on infrastructure which have very long payoff times. M6toll in the UK was built on a 53 year concession: a private company paid to build it, with the right to take tolls on it for the period of the contract (whilst maintaining it), and the road then returns to the government upon the end of contract.The idea that investors are nervous about 30-40 year payback times is nonsense, providing the return is reasonably guaranteed, they love it.

author: tom66
author_rank: Super Contributor
timestamp: February 22, 2024, 09:18:43 pm
content: Quote from: Zero999 on February 22, 2024, 09:14:08 pmAs I said... I don't think they add up either, so I'm not quite sure who you're arguing against! The problem is the cost savings for heat pumps are maybe 10-20% in the optimal case, and 0% or even negative in the suboptimal case. The savings need to be something like 50% with say a 10% spread to make them appealing to the masses. That might happen eventually, especially if efficiencies increase and electricity costs fall as natural gas prices rise, but it's not the case today.However, if you are building a new home, and have the opportunity to install larger radiators, underfloor heating and adequate insulation (as are often the requirements nowadays anyway) I think you would be foolish to install anything other than a heat pump, and I think we should be mandating heat pumps for all new builds. The cost of installing a heat pump in every new build home on an estate is far lower than retrofitting one to an existing property.

author: nctnico
author_rank: Super Contributor
timestamp: February 22, 2024, 09:20:23 pm
content: Quote from: tom66 on February 22, 2024, 09:16:04 pmIndeed. The interest rates on these kind of projects are high and you get a fixed income stream for the decades to come. Ideal for long term investments like pension funds but also small investors are keen on making these kind of investments even though the payback is beyond their grave.

author: Zero999
author_rank: Super Contributor
timestamp: February 22, 2024, 09:24:50 pm
content: Quote from: zilp on February 21, 2024, 09:57:05 pmJust look at the value of gold over the last 100 years. There are peaks and troughs but there's a clear upward trend. Yes I might lose some money, so I certainly wouldn't put all of my money into gold. On the other hand, I know if I replaced my gas boiler with an electric heat pump, it will lose money, so it would be a dumb investment for me. I'm not going to buy a system which will cost a lot of money and cost more to run. It would be like me trying to persuade you into investing in a new paper magazine publication. It will lose money.https://www.macrotrends.net/1333/historical-gold-prices-100-year-chartQuoteWell good for you, but I've hardly used any gas this February because it's been so mild. It's possible I would get a COP of 600% or higher at the moment, since the UK is milder in winter than Germany, but if I'm not using it, then it's irrelevant. I've used my heating a bit this evening because the temperature has dropped to 4°C, but the boiler didn't run for long.QuoteOkay, I accept 350% is a reasonable figure and that I shouldn't just go on the worst case, given others here have told me the same thing.QuoteGiven:The gas engine has an efficiency of 30%The heat pump system a COP of 300%, i.e. for every 100W of mechanical power from the engine, I get 300W of heat.Calculate the total COP of the heat pump, driven from the gas engine:100W of power goes in:The engine is 30% efficient, thus produces:30W power to the shaft, which is delivered to the heat pump, which generates three times as much heat 30W*3 = 90W70W of heat, which isn't wasted but goes into my home.Total heat to my home 90 + 70 = 160W, hence a total COP of 160%QuoteI don't know what the actual cost of a gas powered heat pump is. Yes it would be more expensive, but typically the cost of the heat pump itself is only a small proportion of the total system. At least with a gas powered system, I know it would pay for itself, unlike an electric one. If I've changed my heating to be heat pump compatible and the market changes, I can always move to electric in the future.EDIT:Climate change and politics removed.

author: Someone
author_rank: Super Contributor
timestamp: February 23, 2024, 01:48:40 am
content: Quote from: tszaboo on February 22, 2024, 09:22:38 amOk, so I add back in the original quote tree above rather than your cherry picking and dithering (since you claim to forget why this has happened).Marco points out that thermal ground sources can be cheaply recharged recharged with solar power when it's running in excess and the price of energy is at its lowest.nctnico proposes there are only two possible solutions and says since neither of those is economic then the entire idea is a non-starterI point out that's a dumb simplification as there are other solutions, and include an exampleYou argue that won't work for you and say it is not practical for the majorityI point out that your generalisation is over dramatic and, wrong on several points.There are many ways to get more thermal energy when it's needed. But there are no universal solutions that fit all, or situations that apply to all (beyond the laws of physics...).Always jumping to single solutions for energy are putting up strawmen, 100% solar, 100% wind, 100% CO2 capture, heating only from seasonal storage. They're all as dumb as each other. Most people can and do leverage the diversity of the gird to provide their energy needs, backed with things that are impractical on a domestic level like pumped hydro and nuclear power.Talking about thermal ground sources without considering the energy recharge is just abusing another finite resource, which has little to no oversight. Pretty much the same as logging national parks to burn the wood (there are people doing that too). Tragedy of the common.Quote from: tszaboo on February 22, 2024, 09:22:38 amYou're not needing that, its a want. As has been said repeatedly and in this thread even if heating is a need for health, heating the whole house is still a want.But it seems this thread is now just the (outlier) UK gas price discussion, and the rest of the world still cant talk openly about heat pumps.

author: NiHaoMike
author_rank: Super Contributor
timestamp: February 23, 2024, 03:14:29 am
content: Quote from: Zero999 on February 22, 2024, 09:24:50 pmHow about compare it to just a CHP generator? If gas is so cheap compared to electricity, you could make a profit heating your house. It also wouldn't need any redesign of the plumbing for lower temperature, actually engines don't like to run too cool and so there would be valves to regulate the temperatures.

author: m k
author_rank: Super Contributor
timestamp: February 23, 2024, 07:46:00 am
content: Quote from: Zarhi on February 22, 2024, 08:53:28 amLooks can be misleading.The structure is what it is because air is not dense enough that lesser surface area would be enough.Actual operation happens between refrigerant and inner wall of the pipe.So the machine doesn't know that there is frost, generally it only knows that compression is fine or not.Condenser/evaporator can be insufficient when general operation changes from the normal sufficient operation.It can still be fine with visually not so fine looks.

author: tom66
author_rank: Super Contributor
timestamp: February 23, 2024, 08:14:34 am
content: Depending on the model, some heat pumps just detect that they have fallen in efficacy (due to airflow drop) whereas others do actually measure for ice on the fins.

author: Zarhi
author_rank: Contributor
timestamp: February 23, 2024, 08:26:26 am
content: Quote from: m k on February 23, 2024, 07:46:00 amEvaporator was fully clogged, no air passes at all. And fan operates at very high speed.In this situations heat pump works with COP slightly under 1. Heat dissipated in compressor are transferred to inside unit. Power needed for fan is lost.

author: Marco
author_rank: Super Contributor
timestamp: February 23, 2024, 09:19:52 am
content: Defrost circuitry can be very stupid.

author: tszaboo
author_rank: Super Contributor
timestamp: February 23, 2024, 11:47:04 am
content: Quote from: Someone on February 23, 2024, 01:48:40 amA private individual can only do so many projects at home. Solar is one of them, heatpump is another (which I'm not against, just pointing out how it's not practical for existing homes, after my government forces millions of homes to use). Combined heat and power is feasible, if the government keeps their dirty hands away from our individual freedom, and allows us to connect to the gas grid.So yes, maybe it's possible to resolve these with solar or nuclear or burning peat underground or whatever. I have zero control over that. Solar is great, because it's free as in beers. Any time I need to import energy is just more leverage on my life that I want as much reduced as possible. All the other solutions are just asking for more taxes, fees utility bills. It leads to energy poverty. We want to resolve this global warming situation without causing yet more damage to the standards of living.Quote from: Someone on February 23, 2024, 01:48:40 amI'm done with this part of the discussion. I have the right for this declared by the UN article 25."Everyone has the right to a standard of living adequate for the health and well-being of himself and of his family"I'm sick and tired of people flying in private jets to meeting in Davos, trying to tell us that we have to lower our standards of living, and convincing millions of useful idiots of this. You should stop being a useful idiot. There are ways we can resolve global warming without "depopulation" or "great reset".So I'm going to be very clear about this: You have no right whatsoever to tell me, or anyone else, what I can or cannot have for my standard of living.

author: coppice
author_rank: Super Contributor
timestamp: February 23, 2024, 12:41:06 pm
content: Quote from: Zarhi on February 23, 2024, 08:26:26 amWhere is this located? A heat pump's exchanger needs to be in a place with very freely circulating air. Anything closing it in not only reduces efficiency, as the air recirculates, but condensation builds up much faster. I see lots of people putting the heat exchanger in some dark corner of the world, so it doesn't look obtrusive or to make the noise less obtrusive. Good aesthetics tends to give poor operation.

author: Zarhi
author_rank: Contributor
timestamp: February 23, 2024, 01:05:37 pm
content: Quote from: coppice on February 23, 2024, 12:41:06 pmOne unit is south of the house, second unit is east. Both are in the same condition on same time.But this is no matter. In 2 °C, 60% relative humidity and atmospheric pressure about 1000 hPa dew point is about -4.9 °C. So evaporator will build ice quickly no matter of location, air circulation and so on.This morning was 3 °C, 30% relative humidity and 1012 hPa. Both outside units was clean, no ice at all, and no signs of water underneath them. So last night they doesn't look to defrost at all.PS: Defrosting is clearly seen on graphs.

author: JohanH
author_rank: Frequent Contributor
timestamp: February 23, 2024, 01:06:38 pm
content: Quote from: tszaboo on February 23, 2024, 11:47:04 amI'm flabbergasted that some on this forum can't understand that they are a part of the society like everybody else. As long as we are talking about Europe and democratic societies. The government, that's we, ourselves, whether we want it or not. With such a large population on earth, everyone should understand that they also must be a part of the society, if they want the have the freedoms that the society allows them (but perhaps they could move into an unpopulated area to get total "freedom"). The freedoms are not absolute rights, they are an agreement between us as individuals and the society as a whole. The limits to these freedoms have changed as long as societies have existed and evolved. It's understandable that not everyone want to adapt or change by the changing rules. But as engineers, I would expect some ability to change and adjust circumstances and not just blame the government for everything (it's the same as blaming yourself in the big picture). Why not be creative instead of raging over small things that nobody will care about after a few years? Of course, sometimes changes in society indeed benefits especially a larger population and smaller parts have less benefits, possibly even suffer over some injustice. But I would like to believe that especially people on this forum are creative individuals that are able to adapt, even be the front-runners for changing technology.

author: zilp
author_rank: Frequent Contributor
timestamp: February 23, 2024, 02:38:44 pm
content: Quote from: Zero999 on February 22, 2024, 09:24:50 pmThat is simply a lie. Youdiddiscuss just that, as I quoted above. You just don't want to defend your position when challenged. If you didn't want to discuss it, you wouldn't have mentioned it in the first place.Quote from: Zero999 on February 22, 2024, 09:24:50 pmThat is not all you said. "China, Russia and the USA are never going to adopt net zero" is not a different way of saying "I will choose the most economical heating solution for me". And you know that it isn't.Quote from: Zero999 on February 22, 2024, 09:24:50 pmYeah, but that upward trend still is caused by what I explained above. But if you know not to put all your money into it, that's probably the most important thing.Quote from: Zero999 on February 22, 2024, 09:24:50 pmIt's just that you don't actually know that. Whether replacing a gas boiler with an electric heat pump now is a net profitable decision depends heavily on the development of energy supply costs and the purchase price and installation costs of heat pumps over the lifetime of that (hypothetical) heat pump. And as you don't know any of these to a particularly high degree of certainty, you also can't necessarily know whether installing a heat pump now would lose you money.One thing that is pretty likely, though, for a variety of reasons, is that the price differential between gas and electricity will shrink, and possibly even invert, which at the very least means that betting on gas is not a particularly safe bet.Quote from: Zero999 on February 22, 2024, 09:24:50 pm... which assumes that the exhaust will be at outdoor temperature (i.e., your heating water return is below outdoor temperature?) and at the same absolute humidity as outdoor air (which indeed would be likely with outdoor-temperature exhaust ... but not so much in reality)!?Also, I don't know all that much about the power regulation of combustion engines, but I think that they at the very least have a relatively narrow band of rotational speed where they reach maximum efficiency, and I suspect that exhaust temperature is part of that equation and thus can not be varied continuously to match the water heat exchanger without sacrificing mechanical efficiency!?Which is to say: It seems highly optimistic to me to assume that you could capture 100% of the waste heat for heating purposes.Quote from: Zero999 on February 22, 2024, 09:24:50 pmUh ... I mean, I am sorry, but ... that doesn't make a whole lot of sense!?If you work from the assumption that the majority of the costs of switching to a heat pump are independent from the energy source used by the heat pump, then that implies that switching to a gas-driven heat pump would require the same investment as switching to an electrically driven heat pump. And probably at least a bit more, as you seem to agree. Which also presumably is considerably more than staying with your current system/replacing it with a new gas boiler (as otherwise an electric heat pump would be close to cost parity, based on operating costs alone)? And that difference is supposed to be paid for by a reduction in gas consumption of only 38% even based on your own highly optimistic efficiency calculation?!I mean, I am not saying that it couldn't end up cheaper overall, but I think you are overstating the certainty a lot when you say that you know that it would pay for itself, given the uncertainty of energy supply costs, and the relatively small efficiency gain of a (small) gas-driven heat pump vs. just burning the gas for heat.

author: tszaboo
author_rank: Super Contributor
timestamp: February 23, 2024, 03:28:35 pm
content: Quote from: JohanH on February 23, 2024, 01:06:38 pmPeople care, when they have to declare personal bankruptcy if the boiler in their home stops working. They will first go to the insurance company, that will not cover the installation of a heatpump, because why would they. The government will set up a lousy way to finance it that will not cover anything of the cost.You know what happened here after they made these policies? There was an election, and the far right Gert Wilders won.QuoteThat's what happens. When you make clearly stupid policies that are expensive and don't have support, people fight back, and then you are in a worse shape than making good policies. There are two ways to fight climate change. The wrong way: tax fossil fuels ban cars and force people to do things, leftist policies. Or you can make the alternative cheaper.Cheap renewable energy, and then people switch to that, and they'll be happy with it, and tell everyone how much money they save. Instead we push the leftist policies to the point that people just have enough and decide to do nothing or pollute even more out of spite.

author: zilp
author_rank: Frequent Contributor
timestamp: February 23, 2024, 04:09:56 pm
content: Quote from: tszaboo on February 23, 2024, 11:47:04 amDo you support my campaign for the government keeping its dirty hands away from my individual freedom to put cyanide into your food?If not, why not?Quote from: tszaboo on February 23, 2024, 11:47:04 amYou do realize that this is so vague that noone has any idea what point you are trying to make, right?Quote from: tszaboo on February 23, 2024, 11:47:04 amWhich doesn't answer the question as to whether that is possible.It is an obvious truth that we don't want to reduce standard of living for aynone just for the sake of it.But stating that doesn't do anything to determine whether it is actually possible within the constraints of physics and human mental capacity to resolve global warming without reducing the standards of living of anyone, let alone how to go about it, right?Quote from: tszaboo on February 23, 2024, 11:47:04 amNotice how it says "everyone"? Notice how it doesn't say "tszaboo has the right to a standard of living adequate for the health and well-being of himself and of his family, but fuck everyone else"? Also notice how it doesn't say anything about "a house"?It's actually pretty wild what you apparently think this means. That you even think that this is in any way relevant to your circumstances at all. That you have so little historical and global political awareness that you don't understand that this is about addressing governments leaving people freezing to death in the streets instead of providing them with a little heated room that allows them to survive and to not experience existentially threatening any physically torturing circumstances. That you seriously seem to think that this could possibly mean that the government of your country would be expected to ensure that you are personally provided with 5 GJ of heat per year at discount prices because you have decided that that size of a home is what you need is just completely insane.Quote from: tszaboo on February 23, 2024, 11:47:04 amNow, what relevance do the private jets or the place that these people are meeting have as to the correctness of what they are saying?!Like, if you don't like these people flying in private jets to meet in Davos, ok, fine, I don't like that either. But how does that get us any closer to figuring out whether lowering our standard of living is required or not? Would these same people staying at home and saying the same thing change your mind? And if so ... how does that make any sense?!How about you address the arguments people are making (of which those meeting at Davos really are a tiny minority and generally the least qualified anyway, so why are you concentrating on them?!) as to what (un)viable approaches to solving climate change are and why?Quote from: tszaboo on February 23, 2024, 11:47:04 amWell ... OK?! I mean, I don't even think that any significant number of people suggest that that wouldn't be the case, so ... what is your point?!Quote from: tszaboo on February 23, 2024, 11:47:04 amWell, I am sorry, but that is just obvious bullshit, and I can't believe you actually seriously mean this?!I mean, unless you just mean that noone should have the authority to just arbitrarily force you to reduce your standard of living just because they said so, in which case, OK, I agree, but at the same time, exactly noone is suggesting anything of the sort, so, again, what is your point? Just stating the obvious?I am getting the impression, though, that what you are actually advocating for is that other people should be forced to bear the damages that are caused by your behaviour, because you aren't willing to pay the full costs of your standard of living. And that obviously isn't a reasonable demand.Now, if your argument is that you think that some number of people is already in a position where they have other people, including you, bear the costs of their own standard of living, like, maybe, (some of) the people at Davos, or that some such people are trying to get you to decrease your standard of living in order to allow them to maintain their own standard of living: May I suggest that you have a very close look at who would actually benefit from the policies that you are promoting?Because, to put it very diplomatically: Those organizations that have historically put a lot of effort into lobbying and propaganda for fossil fuels do not exactly have a great track record when it comes to benefiting the general public. Which doesn't mean that there aren't people who have benefited greatly. Some of those you even would have a reasonable chance of meeting at Davos.In particular, these propaganda campaigns tend to abuse the lacking understanding of economic mechanisms in the general public, instead appealing to commonly believed myths (or simplifications, if you want to be charitable) in order to make people support policies against their own self-interest. And some of that I feel can be seen in how you argued in this thread so far--and in particular in how you haven't engaged at all with my explanations as to why I think your suggestions as to how climate change could be addressed more easily and/or more cheaply don't really work out economically. My impression so far from the discussion with you is that you are primarily repeating talking points that you have heard somewhere that seemed convincing to you, as, when challenged, you just switch to a different argument, or you lash out with insults, rather than explaining your position to counter what I am saying. That certainly doesn't match what I would expect from someone who actually has a reasonably deep understanding of a topic.

author: zilp
author_rank: Frequent Contributor
timestamp: February 23, 2024, 04:55:52 pm
content: Quote from: tszaboo on February 23, 2024, 03:28:35 pmDid you notice how you just skipped the important part of your argument?You just say "Or you can make the alternative cheaper."Well. Can you?How?And how isn't that dishonest irrelevant nonsense if you have no idea how?So far, you might as well be saying "Or you can just make CO2 not act as a greenhouse gas". Unless you can support the claim that that is actually possible in the necessary time frame, your statement is equivalent to saying "if we didn't have the problem, we wouldn't have the problem". Yeah, duh? It's just that, in actual fact, we do have the problem, and mere hypotheticals about how we wouldn't have a problem if we didn't have a problem won't do anything to solve the problem that we do in fact have.If you do know of a way to get sufficient cheap renewable energy (and available at the times that it is required, as you correctly noted before in this discussion) to make it an obvious immediate economical win for everyone to switch to CO2 free heating, then please tell us what that way is. But only if you are willing to seriously address the arguments as to why your suggested approach might not actually be as cheap as you think it is. Because we have heard more than enough people who are utterly convinced that their free energy machines work, but who only are that convinced because they never engaged with the explanations as to why they don't actually work. And that sort of argument doesn't get any better if it is based on confusion about economics instead of confusion about physics.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 23, 2024, 07:35:20 pm
content: Quote from: Marco on February 23, 2024, 09:19:52 am"Circuitry" might be a wrong choice of words in 2000's because it's software on a microcontroller. Circuitry is almost always pretty much the same, outdoor air temperature sensor + evaporator coil pipe temperature sensor.There are three classes of defrost logic:(1) Very stupid, which works(2) More sophisticated, which still hopefully works(3) Those that fail more often than once in a blue moonThe simple and reliable baseline is just following the temperature difference between outdoor air and evaporator coil pipe. Once the evaporator is blocked by ice, it getsinternallycolder and colder, which triggers defrosting, which runs until evaporator coil temperature exceeds some high threshold (e.g. +40degC or something) - after the ice has melted, evaporator temperature rises quickly.Stuff like minimum and maximum time between defrosts is usually added. It doesn't need to be rocket science, and while fancier solutions could provide small COP advantages by defrosting just at the right time, the risk of doing it way too often or way too rarely increases with complexity.

author: tom66
author_rank: Super Contributor
timestamp: February 23, 2024, 07:37:02 pm
content: Don't actually expect to "win" any debate on this forum regarding climate change or renewable energy. Goalposts shift, data is ignored, ears are plugged, bullshit is spread. We are heading for climate catastrophe because most humans are fundamentally selfish and cannot conceive of problems outside their immediate interests. Or because that people can't comprehend existential threats. Whatever it is, it's not good.

author: nctnico
author_rank: Super Contributor
timestamp: February 23, 2024, 07:44:07 pm
content: Quote from: tom66 on February 23, 2024, 07:37:02 pmWell, you have to define those 'existential' threats. IMHO the threats are way overblown as the earth and humanity have seen far worse events (like massive vulcanic eruptions, meteorites and ice ages). With today's level of technology there is a lot more the human race can do to remedy effects than ever before. I've been around long enough to notice the climate is changing myself (while carefully keeping in mind that memories typically compress the time frame). I've also been around long enough to know humanity can put serious and effective measures into place to remedy and reverse damage done to the environment. IOW: don't worry too much, it will be OK.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 23, 2024, 07:45:34 pm
content: Quote from: tom66 on February 23, 2024, 07:37:02 pmIn the end, UK remains one of the few outliers where natural gas is 1/4th of the price of electricity. But most of the Earth's population uses heatpumps just fine, because they are hugely popular in most of Asia. Only in the UK, and to some extent, US, heatpumps are conspiracies and scams and whatever. 95% of the planet has no problem with them at all.In this discussion again heatpumps are being compared with PV. I have to again note that both are fundamentally similar, they suck freely occurring energy delivered to us by the big lightbulb called the Sun. The exact pattern is slightly different, and because heatpumps do something PV does not, namely harvest solar energystoredwithin the planet, and I mean not only stored overnight, but also in annual timescale, it is highly valuable, and the value compared to using e.g. li-ion batteries to do the same time-shifting is many orders of magnitude better. The limitation of course then is that the output comes in form of heat, so it can't do everything, but it totally can replace low-temperature heat that would be produced in some other way.

author: coppice
author_rank: Super Contributor
timestamp: February 23, 2024, 07:53:12 pm
content: Quote from: Siwastaja on February 23, 2024, 07:45:34 pmSo, where in Asia are heat pumps popular for heating? There are many millions cooling homes in hot climates, but very few of those are reverse cycle and can heat a home.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 23, 2024, 07:56:09 pm
content: Quote from: coppice on February 23, 2024, 07:53:12 pmYou would be wrong here. While there still are very cheap cooling only window units, and of course the warmest climates mostly do with only cooling, the hugely popular split type air conditioner was originallyinventedin 1980's to be a heating (and cooling) device, and this type is literally everywhere (except UK) since late 1990's.Even in relatively warm climates you need heating during winter months, and quite obviously decent COP can be easily had when "winter" means +5degC not -10 or -30. Such split type air conditioner offers both heating and cooling, both being something people need. It's an optimization to the old days of burning something for heating and using window type cool-only air conditioner during summer. Rest of the world took this step a decade or two ago. Africa included.

author: nctnico
author_rank: Super Contributor
timestamp: February 23, 2024, 08:02:47 pm
content: Quote from: coppice on February 23, 2024, 07:53:12 pmI have a feeling people will want to have heating in the parts of Asia close to the north pole:My previous and current split AC systems can both heat and cool. I got them for cooling as heating makes no financial sense but the heating option is standard on all units they sell here. And even then, I'd favour underfloor heating over an air-to-air unit.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 23, 2024, 08:13:52 pm
content: Quote from: coppice on February 23, 2024, 07:53:12 pmDid you not see the news lately, -52 inChinacouple of day's ago.Maybe a heat pump won't help much with these low temperatures, but as nctnico showed, Asia has some very cold parts.

author: Someone
author_rank: Super Contributor
timestamp: February 23, 2024, 08:18:12 pm
content: Quote from: coppice on February 23, 2024, 07:53:12 pmJapan and China. I'll assume also Korea but would need some other verification of that.

author: tom66
author_rank: Super Contributor
timestamp: February 23, 2024, 08:18:23 pm
content: A regular-old gas boiler will struggle with -52C. For one, the condensate pipe will freeze up quickly, and will require frequent defrosting, but also I doubt the output power of most normal systems could keep up with such extreme weather.In those cases, wrap up warm and use local heating in addition to any central heating.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 23, 2024, 08:32:31 pm
content: Quote from: nctnico on February 23, 2024, 07:44:07 pmDon't be to sure about that.You forgot to mention war as an event that hurts humanity way worse then some of those natural events, and a couple of days ago the news was a bit grim on future expectations. With a big bunch of narcissists controlling the world it might not be so far of. Europe needs to invest in the military apparatus, and count less on America to save our buts. It might be a political scheme to stimulate growth of the defense system and arms economy, but statements were made that we should allow pension funds to invest in weapons industry again.With all the shifts to right wing politics in European countries it could be an indicator of this. Even last election in the Netherlands showed this shift.Lets hope you are right and I'm wrong.On another note, I can remember the times that streets were white and slippery of snow and ice for more than a couple of days in a row, so definitely not denying something in the climate is changing. Caused by industry and burning of fossil fuels, human dreadful interaction with nature or some other natural events, who knows.

author: zilp
author_rank: Frequent Contributor
timestamp: February 23, 2024, 09:03:00 pm
content: Quote from: nctnico on February 23, 2024, 07:44:07 pmDon't you think that it is a bit weird to put "the earth" and "humanity" right next to each other here?! I mean, obviously, the earth has seen far worse times, as far as conditions for life are concerned. Like, the surface of the earth was a molten sea of lava at some point, and obivously, the planet as such survived that just fine. But I presume you don't think that that has anything meaningful to say as to whether humans would be able to cope?!I mean, yeah, I agree, there is absolutely zero risk from climate change to "the earth", as in, the lump of matter that orbits the sun and that we call by that name. All things considered, it will barely be affected. If you go down 10 km from the surface (so not even a percent of its diameter!), there probably would be no way to detect any changes from climate change whatsoever. But the surface could turn back into molten lava, and the same would still apply, so I hope you would agree that that is just completely irrelevant as far as the fate of humanity is concerned?!Now, as for the claim thathumanityhas seen far worse events: Would you mind giving an example of a volcanic eruption, a meteorite, and an ice age, respectively, that humanity has experienced and that you think was far worse than climate change will become for humanity if we don't limit the temperature rise as recommended by the concensus of scientists?To give you a heads up: Modern humans evolved at most 400,000 years ago. The last ice age was ~ 2.4 million years ago. If I were you, I wouldn't waste too much time trying to find an ice age that humanity has experienced.Quote from: nctnico on February 23, 2024, 07:44:07 pmWhat I am wondering is: How would you recognize ahead of time a case where the technology that the human race has available would actually be insufficient to remedy/reverse the damage?Are you saying that it is somehow logically impossible for humanity to cause damage to the environment that it can not remedy or reverse? If so, why would that be? And it not, then how did you determine that this instance of damage to the environment is in the category of cases that can be remedied/reversed?Or are you saying that because we have in the past caused damage to the environment that we were able to remedy, that therefore any damage that we cause to the environment can be remedied?If so, would you see any flaw with it if someone told you that they had been in various car crashes that they had all survived, and that they concluded that it therefore was impossible for them to die in a car crash?

author: coppice
author_rank: Super Contributor
timestamp: February 23, 2024, 09:08:07 pm
content: Quote from: Someone on February 23, 2024, 08:18:12 pmJapan and China have vast numbers of heat pumps for cooling but very few are capable of heating. Japan is strange for an affluent country. Few people seem to properly heat their homes by any means at all, apart from Hokkiado, where its seriously cold. I'm not sure about Korea, but I can't remember seeing heat pumps used for heating there.

author: coppice
author_rank: Super Contributor
timestamp: February 23, 2024, 09:10:56 pm
content: Quote from: pcprogrammer on February 23, 2024, 08:13:52 pmThere are many places in Asia where a heat pump for heating homes would be a great idea, but you just don't see them. The last time I was in China heat pumps for heating hot water were the latest trend, but they were sets specifically to heat a cylinder of water, and not to heat a home.

author: Someone
author_rank: Super Contributor
timestamp: February 23, 2024, 09:57:35 pm
content: Quote from: coppice on February 23, 2024, 09:08:07 pmDoesnt match my experience, and sounds like bullshit when cooling only heat pumps are the rarities on the market. Air-air "reverse cycle" split systems are the majority of installs/models/uses as they are cheap and quickly return the investment compared to alternatives.https://heatpumpingtechnologies.org/market-report-japan/https://www.canarymedia.com/articles/heat-pumps/heat-pumps-are-already-ubiquitous-in-asia-when-will-the-us-catch-up(who links the original sources)

author: coppice
author_rank: Super Contributor
timestamp: February 23, 2024, 11:06:39 pm
content: Quote from: Someone on February 23, 2024, 09:57:35 pmIf he'd looked a bit closer at all those heat pumps on the shops and apartments in Taipei and Ho Chi Minh he would have found the vast majority are air con only. Cooling only units are produced in massive volumes. Maybe you local suppliers sell mostly reverse cycle units, but many countries are different.

author: Someone
author_rank: Super Contributor
timestamp: February 23, 2024, 11:49:12 pm
content: Quote from: coppice on February 23, 2024, 11:06:39 pmCitation required. I provided links and sources, you just talk.

author: coppice
author_rank: Super Contributor
timestamp: February 23, 2024, 11:57:20 pm
content: Quote from: Someone on February 23, 2024, 11:49:12 pmTry walking around Taipei or Ho Chi Minh, and see for yourself. The reserve cycle heat pumps aren't too hard to spot if you recognise the models. You'll find a few. In our tower in HK I think our flat was the only one with reverse cycle units. Taipei and Ho Chi Minh have a similar climate, and a similar mix of air cons and reverse cycle machines.Its hard to tell if the two heat pumps on that restaurant are reverse cycle or not. They look like Daikin units. The consumer sized Daikins are easy to tell apart. The reverse cycle ones are much bulkier and styled differently. Those small commercial ones look similar, although the capacity of the reverse cycle models is lower for the same sized unit. Look at the apartment block behind. Aircons on every apartment, and I doubt a single one is reverse cycle.

author: Someone
author_rank: Super Contributor
timestamp: February 24, 2024, 12:06:09 am
content: Quote from: coppice on February 23, 2024, 11:57:20 pmSo more talk??How about a reliable and neutral source:https://www.iea.org/commentaries/global-heat-pump-sales-continue-double-digit-growthand to quote:Quote from: IEAQuote from: IEAYou're bringing a biased and unsupported position to an easily verifiable argument. Credibility zero.

author: nctnico
author_rank: Super Contributor
timestamp: February 24, 2024, 12:13:13 am
content: Quote from: pcprogrammer on February 23, 2024, 08:32:31 pmThat is a different subject. It is not like the cold-war period or the 1980's in particular where fun times in Europe. We still live and have food on the table. Things need to be shaken up a bit before they get better. Most of the culpritts are rather old and will die (or at least lose power) within a decade or so.

author: nctnico
author_rank: Super Contributor
timestamp: February 24, 2024, 12:29:15 am
content: Quote from: zilp on February 23, 2024, 09:03:00 pmYou are ill-informed then. Northern Europe was covered in a thick layer of ice 20000 years ago. And even more around 115000 years ago. From the latter period it is very easy to see where the ice ended in the landscape near where I live.QuoteYou are seeing that completely wrong. Consider humanity like a bunch of ants in a nest. Some will die and if living conditions get worse, the ants will move somewhere else. Translated to your car analogy: cars are continously improved to become safer in the big picture.Also be aware that nature and the face of the earth change continuously. There is no fixed or final state. One of the major shortcomings of many environmentalists is that they want to keep things the same. If they could, they would want to make the moon stop circling around the earth so to say.

author: tom66
author_rank: Super Contributor
timestamp: February 24, 2024, 12:42:22 am
content: Why are we even bothering to compare whether humans lived 20,000 years ago in an ice age or not? It's irrelevant. Utterly irrelevant. Life expectancy was shorter in those times too, turns out temperate climates are about right for humans. It isn't conducive to survival to be in extreme weather of any kind. But it's not representative of the threat of climate change.The problem with climate change is not human extinction, no one serious thinks humans will go extinct, it is the severe and irreversible harm it will do to an ecosystem that is currently well balanced, that is currently able to feed approximately 7 billion people adequately (and another ~1 billion inadequately). It is the threat to arable land especially in equatorial areas. It is the flood threat to countries with limited sea defences. It is the extreme temperature and drought threat to most countries 15 degrees either side of the equator.Upset the delicate balance and trigger these events and you will have war, famine and illness - that is the big danger of climate change - not slightly hotter summers or colder winters.

author: coppice
author_rank: Super Contributor
timestamp: February 24, 2024, 12:45:43 am
content: Quote from: nctnico on February 24, 2024, 12:29:15 amThere is plenty of evidence that people followed the retreating ice sheets into northern Europe, as the last ice age cycle subsided. Ice ages cycle about every 100k years, and have been doing so for numerous cycles.

author: nctnico
author_rank: Super Contributor
timestamp: February 24, 2024, 12:59:57 am
content: Quote from: tom66 on February 24, 2024, 12:42:22 amThere is no such thing as a delicate balance. There is only chaos in the weather system. You can't even be 100% sure that the temperature change we're seeing is due to human activity. There are so many factors that you can't even begin to create a suitable model. For starters take the huge amount of energy the sun is supplying to the earth. Even a small fluctuation can have a massive effect and this happens as the sun's energy output isn't constant at all. Data shows that sun has been outputting more energy since 1700. But you can't even start to claim that causes an increase in temperature. It might as well cause a decrease in the long term. Nowadays the news is way to quick to attribute every bit of rain (or lack thereof) to climate change. Accurate data goes back only 100 years or so.

author: zilp
author_rank: Frequent Contributor
timestamp: February 24, 2024, 01:09:50 am
content: Quote from: nctnico on February 24, 2024, 12:29:15 amWell, that depends on what exactly you mean by "ice age".But it doesn't really matter anyhow, as even a mere 20000 years ago there was nothing close to the current human population, so the fact that (some) humans survived that time doesn't tell you anything useful for today anyhow.Also ... what about the volcanic eruption and the meteorite?Quote from: nctnico on February 24, 2024, 12:29:15 amOK. And how many humans do you expect to die? And where do you think the remaining humans will move?Quote from: nctnico on February 23, 2024, 07:44:07 pmYeah. But you do understand that there is a limit to how bad of a crash a modern car with all the state of the art safety systems will save you from, right?Quote from: nctnico on February 23, 2024, 07:44:07 pmOK. And how is that relevant here? What does that have to do with climate change, or with whether there is reason to worry, or ... anything in this dicussion?Quote from: nctnico on February 23, 2024, 07:44:07 pmPlease provide a source for that claim.

author: zilp
author_rank: Frequent Contributor
timestamp: February 24, 2024, 01:24:13 am
content: Quote from: nctnico on February 24, 2024, 12:59:57 amYou are aware that you are in disagreement with about everyone who does research in that area professionally, right?Quote from: nctnico on February 24, 2024, 12:59:57 amYou are aware that "the weather system" is to climate as "resistor noise" is to an amplifier, right? Do you also think that amplifiers don't produce any useful signal because the resistor noise in the bias resistors is only chaos?Quote from: nctnico on February 24, 2024, 12:59:57 amAre you saying that you can only be 99% sure, or are you saying that you can only be 1% sure?If the former: How is this a relevant objection, then?If the latter: You are aware that you are in disagreement with about everyone who does research in that area professionally, right?Quote from: nctnico on February 24, 2024, 12:59:57 amYou are aware that you are in disagreement with about everyone who does research in that area professionally, who also happen to be aware of the sun's behaviour, right?Quote from: nctnico on February 24, 2024, 12:59:57 am... so? Do you think that because some news journalist says some nonsense, that therefore, there is noone on the planet who actually has a clue on the respective topic? Like, how is this relevant here?Quote from: nctnico on February 24, 2024, 12:59:57 amYou are aware that scientists who work on climate change have many natural data sources that go back way longer than human weather records, right?In particular, you did notice that you seem to be convinced that there was significant glaciation about 20000 years ago, even though that is in fact longer than 100 years ago?

author: johansen
author_rank: Super Contributor
timestamp: February 24, 2024, 01:31:25 am
content: Is this what this forum has become? 5% useful posts on actual heatpump data, 95% argument?

author: Monkeh
author_rank: Super Contributor
timestamp: February 24, 2024, 01:34:46 am
content: Quote from: johansen on February 24, 2024, 01:31:25 amWelcome to the internet.

author: Someone
author_rank: Super Contributor
timestamp: February 24, 2024, 02:04:47 am
content: Quote from: johansen on February 24, 2024, 01:31:25 amSomething about heatpumps brings out the crazies, not just this forum. So the OP asking for honest answers (being overwhelmed by the noise) is fully understandable.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 24, 2024, 04:04:15 am
content: Quote from: coppice on February 23, 2024, 09:08:07 pmTotal bullshit. You only have to visit these countries to see. Africa pretty much the same. The reason they are used for heating is not only environmental, or good COP. It's convenience. One single unit does both, so you don't need separate systems for heating and cooling. In climates where heating needs are modest, having a separate system when your "cooling" unit can do the same is just insane. Similarly, wrapping in blankets in cold moist winter days without heating is just insane when you can have heating from the same heatpump by paying $50 more for the unit. And electricity in these countries is cheaper than it is for you in the UK. Even if you are very poor and saving in heating or cooling cost by heating/cooling less, you would still have the system.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 24, 2024, 08:00:33 am
content: Quote from: Someone on February 24, 2024, 02:04:47 amLuckily I'm able to filter the noise and as I wrote earlier I got the answers I was looking for. Now I participate in the noise too.I read in a book of a Dutch guy that the IPCC does not see cities to be a contributor to the climate change. All I could find was that they seecitiesas high risk areas due to climate change. They just focus on CO2 as the big culprit in the whole climate change.My opinion is that this is short sighted, and that there are many more factors in play.Paving the planet with solar panels or harvesting all the lithium in the world, etc, might only make things worse. Humanity is it's own worst enemy. We poison our planet just to make a couple of bucks. I'm no exception. We try to do our best with reducing on consumption, but still want to have a bit of fun and luxury, so yes I buy things on Aliexpress and we live in a very big house.A delicate balance was mentioned in some posts. One thing humanity is not capable of, keeping balance.Edit: A Dutcharticleabout the writer of the book I mentioned.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 24, 2024, 08:29:08 am
content: Quote from: pcprogrammer on February 24, 2024, 08:00:33 amDon't take it too extreme, but there is something to this. Efficient solutions should be preferred and e.g. a simple air-to-air heatpump which costs 500€ to buy and uses a few dozen kg of common materials like plastics, iron, aluminum, copper, yet harvests 1kW (input power) * 2 (SCOP-1) * 24*365 * 0.5 (duty cycle) * 12 (years lifetime) = 100 000 kWh of free, renewable energy. A 4-5kWp PV system would then harvest say 5000 kWh/year * 20 year lifetime = roughly the same 100 000 kWh of free, renewable energy.But the environmental cost of manufacturing the heatpump is probably smaller, it is significantly cheaper to buy, and it harvests energy during winter nights, too. This doesn't mean PV is bad, just something to think about for the priority list.Lithium ion battery storage is then again at least an order of magnitude worse again. Especially if you have any low-hanging fruit like controlling the usage of electric hot water production which caneasilystore 20kWh worth of energy by just adding 500€ worth of control to an existing system. Compare the ecological footprint and install cost to li-ion battery system of the same size!Then again, maybe such low-hanging fruit is not available. I'm not saying never to install battery systems. Just something to think about for priorities.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 24, 2024, 09:03:32 am
content: Quote from: Siwastaja on February 24, 2024, 08:29:08 amDon't get me wrong, I neither am saying not to take action, but indeed think about the action you are taking and don't willy-nilly buy into what the media or politics is trying to shove down your throat.The whole idea of these systems to pay for themselves is kind of bullshit. Sure it can reduce on your energy bill, but it will still cost money. Depending on the type of system and the cost to install it can take a long time before any savings start to come. You will have to take into account the loss of interest or dividends the sum you are spending on such a system might have given you too. Won't be much for a system of a couple of grand, but when it becomes 10 or more K's it adds up.So for us we just see it as cost for living in comfort and not as a way to save money. Living costs money is a simple fact of life. That we might help in "saving the planet" is a small bonus.As is, it is more likely helping the economy.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 24, 2024, 09:31:32 am
content: Quote from: pcprogrammer on February 24, 2024, 09:03:32 amRemember that expensive systems such as quoted for you are a kind of specialty of wealthy societies and wealthy households. Energy solutions are being sold exceeding their true value, because there is market for that and people still buy. My air-to-water heat pump installation was less than 4000EUR all parts included, although I did the install work myself but it would have been less than 1000EUR for work if I just paid for hourly rates for electrician and plumber; and the end result is way better than how a typical 15000EUR complete one size fits all solution would have been.Typical cost for air-to-water retrofit was around 8000-9000 EUR here but nearly doubled to 14-15000 EUR almost overnight after a 4000EUR subsidy come into place. The market does not reflect actual costs, and any subsidies further twist the market. Enough people are willing to pay outrageous prices when theyfeelgood about it.In Japan air-to-air heatpump costs something like 500EUR installed so one can easily afford one per each room. They do pay back for themselves, that's literally why they were developed in 1980's in the first place, to save cost of fossil fuels.

author: nctnico
author_rank: Super Contributor
timestamp: February 24, 2024, 10:15:42 am
content: Quote from: Siwastaja on February 24, 2024, 09:31:32 amThat is absolutely true. About a year ago I did a DIY solar panel install costing me around 3700 euro in parts. To have it installed I got quotes for nearly double that price. But that was during a period of extreme hype so installers could ask any price and people would pay for it. My solar panel system will still pay for itself in 3 years though.Now I'm looking at putting a 'green roof' on the shed (just for kicks and because I like growing plants). Due to subsidies this is insanely expensive to buy off the shelve. Unfortunately I don't have time right now to execute a DIY solution I came up with.

author: tom66
author_rank: Super Contributor
timestamp: February 24, 2024, 10:25:33 am
content: Quote from: Siwastaja on February 24, 2024, 09:31:32 amIndeed. It is kind of bonkers how expensive heat pumps are to install professionally. I can buy a monobloc unit for my house for about £4,000. That replaces the boiler and provides heat. I would need a hot water tank (for on-demand hot water) and some plumbing work to complete it, but to get this work done professionally would cost around £12,000. There are only a limited number of professionals that can do this work, and they are in high demand. We have really dropped the ball when it comes to skilled trades, instead of sending kids to trade schools we're sending them to get pointless degrees in subjects they don't need or want. (Rant over.)

author: Zero999
author_rank: Super Contributor
timestamp: February 24, 2024, 10:27:53 am
content: Quote from: zilp on February 23, 2024, 02:38:44 pmNow it appears you're tying to provoke me, which will not work. I'm more than capable of defending my position. Indeed I consider it to be fairly obvious. I just do not want to discuss the matter here any more. For one it's against the rules of this forum and secondly I know from previous experience it's impossible to discuss such matters in a logical manner with those who resort to accusations of lying. It'll just result in pages of arguing, the thread being locked and possibly both of us being banned. It's just not worth the bother. This is me exercising self-control. There is a part of me that really wants to write a long rebuttal to your post, but I know better.QuoteI have done the calculations, as has someone else here, who is also an advocate of heat pumps.https://www.eevblog.com/forum/chat/what-is-the-real-story-around-heat-pumps/msg5347484/#msg5347484QuoteAnd guess what. If it becomes economical for me to buy an electric heat pump, then can do it. It's just uneconomical at the moment. I don't see why you appear to be having difficulty understanding that.QuoteNot highly optimistic, only a little optimistic to assume all of the heat from the engine will heat my home. Perhaps 85%, is a more reasonable figure, similar to a condensing gas boiler. This still a COP of around 150% and is much cheaper to run than electricity of a condensing gas boiler.QuoteTo be honest, changing to a heat pump, whether it's powered from electricity, or gas wouldn't be worth it for me at the moment because my energy usage is too low for it to matter. It's really a thought experiment.

author: nctnico
author_rank: Super Contributor
timestamp: February 24, 2024, 10:37:02 am
content: Quote from: zilp on February 24, 2024, 01:24:13 amCitation needed... Maybe you should actually do some research into the subject like I did for over 25 years already.If you start looking carefully you'll notice that a lot of data is being filled in by assumptions and thus the 'conclusion' is only an assumption. Trying to model something erratic as weather / climate is next to impossible so anyone claiming to have an absolute truth in that area is leaving out a lot of details which may even prove that person wrong. There are some long term effects (like recurring CO2 peaks every 40000 years, long term/short term sun cycles, cold / hot periods centuries ago, etc, etc) which are not explained by models used for global warming. In the end global warming predictions are a line fitted onto the temperatures from the last 100 years with the assumption that CO2 levels are the major factor driving the temperature up.In fact, there are several other way more pressing issues which make that we should stop burning fossil fuels:1) Burning fossil fuels is very bad for our health. We should have switched to nuclear a long time ago. Even with some more nuclear power plants blowing up, this would have saved and continue to save millions of lifes.2) The CO2 level in the atmosphere is creeping up to levels where CO2 becomes toxic to humans, animals and even plants. Look at the coral reefs as an example.3) Fossil fuels are finite. Once they run out, there has to be an alternative or society will collapse.4) Taking rising CO2 levels out of the equation as a cause of continued global warming.Now look at this list through the eyes of a politician. Fear is an effective driver to make people vote for you. So which point to latch onto for a fear mongering campaign? Point 1 will get a lot of pushback from environmentalists who are dead set against nuclear. CO2 toxic? Finite fuels? Global warming? Global warming has a nice ring to it and there are alarmists claiming the world will end if we don't do something so that is free publicity. Notice that the effects of global warming are on the longest term of all the points I listed and there is no certainty stopping burning fossil fuels will actually stop global warming.IOW there is a good reason that people are getting fed up with fear mongering and start to vote for right wing politicians which want to continue burning fossil fuels. In turn this circles back that renewable energy sources and reduction of energy usage needs to be made cheap enough for the masses.

author: Zero999
author_rank: Super Contributor
timestamp: February 24, 2024, 10:45:39 am
content: Quote from: Someone on February 24, 2024, 02:04:47 amBecause it's political. I'm not going to get into who's right and wrong in this post, just explain why many get emotional about it, briefly outlining both points of view.Many western governments are implementing net zero policies and are pushing associated technologies such as heat pumps and electric cars. On one side there are those who strongly support such measures, which they see as important to combat the existential threat posed by climate change. On the other side, there are those who see such policies as unwanted state interference and authoritarianism and that it is such governments themselves who are the existential threat, rather than climate change.

author: Someone
author_rank: Super Contributor
timestamp: February 24, 2024, 11:10:47 am
content: Quote from: Zero999 on February 24, 2024, 10:45:39 amBut the only politics seems to be in the supply/price of natural resources. Nothing to do with the heat pump.All it needs is people plainly stating the reason why they think their position, instead of non specific unarguable generalisations.Most of this thread is UK people dodging the fact that their energy costs are abnormal, while making all sorts of big claims about the rest of the world. Obnoxious colonialism vibes.

author: Zero999
author_rank: Super Contributor
timestamp: February 24, 2024, 11:20:56 am
content: Quote from: Someone on February 24, 2024, 11:10:47 amAnd from my position, I see this thread as a load of Europeans lecturing us Brits telling us what to do.Are you trolling now by mentioning colonialism? It's irrelevant. It has nothing to do with colonialism and all to so with people making generalisations, which is inherent to human nature. The Europeans and Americans do the same thing.I accept what might be the most economical solution for me, won't be the case for others. For the purposes of this thread, it doesn't matter why energy prices are what they are. It's outside the scope of this forum.

author: coppice
author_rank: Super Contributor
timestamp: February 24, 2024, 11:38:07 am
content: Quote from: Zero999 on February 24, 2024, 11:20:56 amNobody can tell someone from another part of the world how to deal with resource hungry things (e.g. energy), or their environment. Supply chains and environments are so location specific. This probably has a lot to do with people misinterpreting what they see and read, because they are projecting from their own position.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 24, 2024, 12:12:10 pm
content: Quote from: Zero999 on February 24, 2024, 11:20:56 amNot at all. You would be a foolnotto take advantage of the very cheap natural gas. That said, on the level of country, it's sad to see how expensive electricity is for you, because electricity is so flexible and useful.

author: AVGresponding
author_rank: Super Contributor
timestamp: February 24, 2024, 12:20:51 pm
content: As it happens, we are installing an air-source heat pump at a community youth centre we are rewiring. I shall provide some pics and COP info at some point in the near future...

author: zilp
author_rank: Frequent Contributor
timestamp: February 24, 2024, 12:38:20 pm
content: Quote from: Zero999 on February 24, 2024, 10:27:53 amYou really need to pay attention. I didn't say you wouldn't be capable of defending your position. I said you didn'twant to defend your position. Look at it, it's right there in the quote that you are responding to. Now, you aren't trying to tell me that you wrote "I'm just not going to discuss net zero, propaganda and taxes" because you wanted to tell me that you were intent on defending your position, are you?Quote from: Zero999 on February 24, 2024, 10:27:53 amI supposed as much. But you do notice how that is a pointless statement to make, right?Quote from: Zero999 on February 24, 2024, 10:27:53 amWhich might be true or not. But that doesn't change that it is dishonest to first throw out a statement that you know is controversial, to say the least, and then pretend that it's a claim that you don't want to talk about. Obviously, you would be willing to talk about it further if you were getting agreement. If it were in fact something that you didn't want to talk about, you wouldn't talk about it. But you obviously did talk about it. And you obviously weren't forced to, either.Quote from: Zero999 on February 24, 2024, 10:27:53 amIt's funny how the problem apparently is that someone is pointing out that you are in fact lying, isn't it?Quote from: Zero999 on February 24, 2024, 10:27:53 amNowhere in that post that you are linking to is there any attempt to model the future costs of the respective systems, so that obviously is not a relevant response to what I wrote. And also, it is obviously nonsensical to say that you have done the calculations in response to me pointing out that you don't know the numbers that you would need to do the calculation without saying a single word about how you do know the numbers after all.Quote from: Zero999 on February 24, 2024, 10:27:53 amBecause that isn't how economics works. To make an obvious example to illustrate the problem: If gas goes to 50 p per kWh tomorrow and stays there for the next ten years while electricity doesn't change, then the total costs of an electric heat pump installed at current prices would probably be lower than a gas boiler. But at that point, because of that change in gas price, the installation costs for heat pumps will shoot up, because the supply of heat pumps and of heat pump installation work is close to fixed in the mid term, so the massively increasing demand will drive the price up (to the new equlibrium point), so you can't actually buy a heat pump at that price then anymore.You are essentially saying that you can still buy gold tomorrow if you see that the price has increased.And just to be clear: No, 50 p per kWh tomorrow is not likely. The point is to create an obvious example to illustrate the problem. Though we did see similar scenarios play out at the start (or whatever you want to call February 2022) of the Ukraine war: People who had installed heat pumps or solar systems recently at prices where they weren't expecting break even any time soon, if at all, at the then-current energy prices suddenly realized that they had made a profitable investment, while others, who got the idea to avoid the increased energy prices by putting in renewable sources found that the prices for doing so had adjusted to the point where it wasn't a clear win anymore.Quote from: Zero999 on February 24, 2024, 10:27:53 amIt's just that I don't see any reason to assume that you would be able to achieve that efficiency, which is what I was trying to tell you. The efficiency of a condensing boiler comes from low temperatures, which is what allows the condensation to happen. But for one, it isn't obvious that you can actually control the exhaust temperature that well without sacrificing mechanical efficiency, because, see above. But also, you then have the choice to either use the exhaust to heat up the return before the heat pump, which is at the lower temperature and thus allows for more condensation, but which drives up the return temperature seen by the heat pump and thus reduces the efficiency of the heat pump, or you can heat up further at the output of the heat pump, in which case you get higher efficiency of the heat pump, but higher temperature in the exhaust heat exchanger and thus less condensation and thus lower efficiency in the use of waste heat.Quote from: Zero999 on February 24, 2024, 10:27:53 amWell, yeah, sure, but I would think that it wouldn't be an obvious economic win even if your heat use was closer to the average.(And for that matter, it wouldn't necessarily be an ecological win either to swap out a working gas boiler that isn't used that much overall ...)

author: Zero999
author_rank: Super Contributor
timestamp: February 24, 2024, 12:49:17 pm
content: Quote from: zilp on February 24, 2024, 12:38:20 pmI was not the one who first raised the issue of net zero, which is a controversial and political point and is against the rules of this forum.I should have just reported it to the moderator, but made an error of judgement and responded to it.It appears as though you just want to ague now. I have no intention of responding to your disingenuous posts.

author: zilp
author_rank: Frequent Contributor
timestamp: February 24, 2024, 12:50:52 pm
content: Quote from: Zero999 on February 24, 2024, 11:20:56 amExcept it totally does matter, because that is what can inform you about how prices will change in the future, and thus about what investment decisions now will pay off later.This is like saying the reasons for the chip shortage are outside the scope of this forum, just because the causes of the shortage are not something traditionally covered by an EE curriculum. The reasons very much are relevant if you want to make an informed decision as to how to deal with the situation.

author: zilp
author_rank: Frequent Contributor
timestamp: February 24, 2024, 01:07:33 pm
content: Quote from: Zero999 on February 24, 2024, 12:49:17 pmErm ... you seriously think that just because someone on the planet thinks that something is controversial, therefore, it is against the rules? So, mentioning that the earth is a globe is against the rules because there are people who are convinced that it ain't so?! Saying that free energy machines don't work is against the rules because there are people who think that the knowledge is suppressed by dark cabals?!I mean, using a "lefty" label to try and discredit someone's position is obviously a political maneuver that I would think is against the rules as it obviously can not contribute anything constructive to a discussion. Stating and explaining facts about reality ... no so much.Quote from: Zero999 on February 24, 2024, 12:49:17 pmYeah, sure. I totally believe you.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 24, 2024, 02:07:18 pm
content: Quote from: tom66 on February 24, 2024, 10:25:33 amA tip, assuming you have either a boiler, or a separate storage tank with, with heat excharger for domestic how water. Plumbing: connect the monoblock to feed heated water into the boiler or storage tank, with the heatpump's own curve as optimized for house heating needs. You then get lukewarm "preheated" DHW out of the existing heat exchanger, so all you need it to install a small electric boiler "in series". Given that it only needs to heat the water from say 30..40degC to 60, not from 10 to 60, it can be a small one, one of those you would normally use for heating water for a single sink or in a small cabin. A 60-liter, 2kW boiler has served this purpose for me very well.During summertime, especially if you use a lot of hot water, you are losing in COP. In winter, not so much, because the "incremental" or marginal COP above the house heating temperatures is close to 1.0 anyway, even if you use compressor.This way, you don't need a motorized turnover valve or two large-ish storage tanks, and also get 100% duty cycle (minus defrosts of course) for house heating during the coldest of times. A simpler and lower cost system for retrofits, especially DIY. Has served me well. Annual loss of COP is probably not much but I haven't exactly calculated it. Professionals probably hate the idea, just like they hate monoblocks.

author: zilp
author_rank: Frequent Contributor
timestamp: February 24, 2024, 02:19:05 pm
content: Quote from: Siwastaja on February 24, 2024, 02:07:18 pmBeware of legionella, though, if you have a storage tank that is filled with DHW (as opposed to a storage tank with a low-volume heat exchanger for DHW).

author: Zero999
author_rank: Super Contributor
timestamp: February 24, 2024, 02:20:17 pm
content: It appears as though a few people, including myself, have forgotten the forum rules, so I thought I'd post a quote to serve as a reminder.Quotehttps://www.eevblog.com/forum/chat/forum-rules-please-read/In light of this. I have gone back and edited some of my posts, removing references to politics, net zero being one of them. If anyone spots a post I've missed, please either report it to the moderator, or just drop me a private message. I have also reported several posts to the moderator. I strongly recommend others do the same.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 24, 2024, 02:26:51 pm
content: Quote from: zilp on February 24, 2024, 02:19:05 pmThat's why you set the electric boiler to maintain at least 60degC. Which is actually more idiot proof, given a simple mechanical thermostat, than a complex system with turnover valve and two tanks heated by a heatpump and controlled by the heatpump's (possibly buggy or hard to configure) control system.Another plus side for my proposal is that you will have an independent back-up system for DHW, just smaller capacity, which Just Works without modifications even if the heatpump fails.

author: zilp
author_rank: Frequent Contributor
timestamp: February 24, 2024, 03:27:53 pm
content: Quote from: Siwastaja on February 24, 2024, 02:26:51 pmI'm not sure that that would be sufficient with a DHW storage tank!? AIUI, the problems is that the large volume (a) means that the concentration of bacteria never gets reduced much if they ever are established because use of hot water only dilutes things a bit while the growth is exponential and (b) sediments will settle in the tank, which adds additional protection for the bacteria from being cleaned out from the tank. At the same time, killing a high-ish concentration of bacteria down to a low-risk level would require heating to 60°C for many minutes, maybe up to 30, which a simple electric boiler at the output can't do. To kill them in seconds would require 70°C or more. Or you would have to occasionally heat up the tank to 60°C using the boiler somehow.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 24, 2024, 03:39:56 pm
content: Quote from: zilp on February 24, 2024, 03:27:53 pmNo need to overthink. Just set to 60degC. Water is always held at 60degC (plus minus hysteresis of thermostat, and small excursions during heavy water use, but that's only for a short time). This is OK at least per legislation here. Maybe some other country requires 55 or 65degC. Set it to +70 with a further small decrease in total COP, if worried.And this is definitely safer than than the "official" way of doing it offered by heatpumps, namely heatpump maintaining 50-55degC in DHW tank, which is a tad too low, with a 60-65degC "legionella" program running once a week. The risk is this program being too short or failing somehow. Even then, I'm not aware of any actual problems.You probably did not understand what I suggested from my description in the first place, and being lazy I'm not going to try to draw a picture of it right now so just reread carefully my (possibly poor) explanation. Single storage for house heating -> pre-heated lukewarm DHW through existing heat exchanger -> small electric boiler in series to final temperature. This small boiler sits at high temperature all the time.

author: zilp
author_rank: Frequent Contributor
timestamp: February 24, 2024, 04:24:16 pm
content: Quote from: nctnico on February 24, 2024, 10:37:02 amhttps://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_SPM.pdf, search for 'tipping'.Quote from: nctnico on February 24, 2024, 10:37:02 amYou do realize that you have no idea how climate models actually work, right? The idea that somehow it is all based on weather data of the last 100 years is just ... wild.Also ... why would you possibly expect a climate model of earth to explain sun cycles?! Sun cycles are obviously aninputto climate models, not something that they try to explain!?And also, who has ever claimed absolute truth? Are you saying that we should ignore risks unless we are absolutely certain that they will be realized?Oh, and also ... now, what is it, is the climate chaotic, or is there not a delicate balance? You can't have it both ways. Either there are forking points where minor perturbations in inputs are amplified into huge effects or there aren't.Oh, and ... why are you still mentioning the weather? How is chaotic behaviour at the micro scale relevant for the macro scale of climate?Other than that, your objections really are just too vague to be useful.Quote from: nctnico on February 24, 2024, 10:37:02 amWhich is all based on the baseless assumption that it is fear mongering. So, you are just assuming your conclusion. If it is a real danger, then politicians acting to mitigate the risk are not fear mongering, and just claiming that it is doesn't create a good reason to be fed up with what they are doing.Quote from: nctnico on February 24, 2024, 10:37:02 amWhich still is a useless statement if you can't explain how that could be done.

author: zilp
author_rank: Frequent Contributor
timestamp: February 24, 2024, 04:39:14 pm
content: Quote from: Siwastaja on February 24, 2024, 03:39:56 pmWell, the preferred way is to not have a DHW tank at all, but only a storage tank with a heat exchanger for DHW, so that there is no significant volume of DHW at problematic temperatures, and what is there is cleaned out completely whenever you use hot water.Quote from: Siwastaja on February 24, 2024, 03:39:56 pmI am still not entirely sure what exactly you mean, but also, my response wasn't necessarily relevant to your specific setup, just a warning of something to consider.If you mean a storage tank filled with non-DHW that is kept warm by the heat pump and a DHW heat exchanger in that tank (I think that that is what you are describing?), then that should be fine because there is no significant (dead) volume of DHW kept at problematic temperatures for a long time, so, with regular use, you shouldn't ever get any persistent high legionella concentrations.The problem arises if you have a storage tank with DHW in it, which you could possibly keep at 30 to 40°C with the house heating heat pump as well, but then I would think that an electric boiler at the output heating the water to 60°C would not be sufficient to kill the legionella if they were to get established at high concentrations in the tank.

author: NiHaoMike
author_rank: Super Contributor
timestamp: February 24, 2024, 04:58:45 pm
content: Quote from: Siwastaja on February 24, 2024, 03:39:56 pmIn the US, the solution (at least for the majority on city water) is the water has chlorine or chloramine added. The recommended hot water temperature is 120F as the risk of burns increases dramatically beyond that.Another solution would be to have a UVC light inside the tank. My guess as to why that's not common is simply because there's no need for it with city water.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 24, 2024, 06:35:53 pm
content: Quote from: zilp on February 24, 2024, 04:39:14 pmDHW tanks are super popular here, during the era when electric radiator heated houses (with no hydronic distribution) were built starting from 1980's (after the oil crisis). Most are made of stainless steel and it was really popular to automagically time them to use nightime tariffs for which 300 liters was a usual volume and 3kW the usual power. Smaller volumes for continuous operation. No one here considers them problematic at all. They are clean from biological growth because of the temperature, and last easily for 30-40 years. But clearly different solutions are popular in different countries. The small ones cost just a few hundred €. It's easy to put one in series to get to high enough water temperature if you have an "easy" (and high COP) source of preheated but not warm enough DHW, which is often the case in monoblock air-to-water retrofits in existing systems which did earlier use higher temperature in a tank with heat exchanger as explained by you.

author: nctnico
author_rank: Super Contributor
timestamp: February 24, 2024, 06:56:23 pm
content: Quote from: NiHaoMike on February 24, 2024, 04:58:45 pmThat is too low to protect against legionella. And there can be other parasites in the water as well which are chlorine resistant AND can make you quite sick. So I'd keep the water temperature high. However, I can highly recommend getting a thermostatic tap for shower(s) and bathroom sink(s). They are limited to a safe temperature. And it saves quite a bit of water because it reaches the setpoint temperature quicker compared to manual mixing.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 24, 2024, 07:01:27 pm
content: Quote from: nctnico on February 24, 2024, 06:56:23 pmThis underlines how cultural differences affect engineering. In the land of freedom and lawsuits, you use chemical warfare against the threat, but you want to avoid hot water being hot because someone could get burns and sue. I'm sure it works there. Here we just try to carefully adjust our mixing valves to 60degC which is just enough to kill legionella and just low enough to at least avoidseriousburns even though someone who is very careless could get minor burns. And we think it's parent's job to keep children away from dangerous stuff.

author: zilp
author_rank: Frequent Contributor
timestamp: February 24, 2024, 07:10:39 pm
content: Quote from: Siwastaja on February 24, 2024, 06:35:53 pmOh, you are talking about a boiler in a tank? I thought you meant just a (flow-through type) boiler with minimal water volume. That should help, too, I guess.Well, there are man ways to solve this, the important point is, whatever you do, pay attention to legionella!

author: JohanH
author_rank: Frequent Contributor
timestamp: February 24, 2024, 07:15:07 pm
content: Quote from: nctnico on February 24, 2024, 06:56:23 pmI guess it's very different in different countries. We are spoiled with very clean ground water in all of Finland. In our town it's taken straight from the ground and you can drink it from the tap as is. Everyone does! As for the hot water, in our house it's heated by the ground source heatpump to about 50 degrees C (in a 180 l tank) and twice a month it's heated to 60 C. There's a thermostat after the heat pump that mixes it down somewhat. Everyone that I know have thermostatic taps in their shower. I considered also putting a small electrical DHW tank in series, but it isn't needed for our hot water consumption (I know many does this over here). It's exactly as Siwastaja explained, they are used to "top up" the hot water and to get more capacity. I have never heard of any legionella or any other problem due to hot water over here, so I guess the legislation is enough.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 24, 2024, 07:27:09 pm
content: Quote from: JohanH on February 24, 2024, 07:15:07 pmThis is what everyone "by default" does with heatpumps (ground source or air-water), because it's as implemented by the pump manufacturers, and I know it practically does not cause problems, but it strictly is illegal; the legal minimum continuous temperature is 55degC (of course very short excursions would be allowed, but "all the time except every two weeks" doesn't cut it). Specifically, 60degC is not enough for a "kill" program unless it's very long.The legal range is here in 6§:https://www.finlex.fi/fi/laki/alkup/2017/20171047: 55 to 65 degC. It's quite strict and I'm sure 80% of households doesn't meet these limits, yet legionella outbreaks are still very rare, because the actual high-risk region is more like +30 - +45 degC.Low side of that range needs to be exceeded by the storage tank itself; high side can be shunted down by thermostatic mixing valve as usual.

author: nctnico
author_rank: Super Contributor
timestamp: February 24, 2024, 07:28:51 pm
content: Quote from: JohanH on February 24, 2024, 07:15:07 pmThe same goes for the NL. In most cities the water from the tap is cleaner compared to bottled water. Nevertheless, ground and surface water does contain legionella and it could grow given the right circumstances. Legislation is greatly depending on what kind fo serious outbreak has occured or not. In the NL (around)15 people died in a single incident due to a legionella outbreak so more legislation was put into place.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 24, 2024, 07:45:41 pm
content: Quote from: nctnico on February 24, 2024, 07:28:51 pmYou mean this one:https://en.wikipedia.org/wiki/1999_Bovenkarspel_legionellosis_outbreakTypical legionella cases seem to be:* Hot tubs that are kept at around 37degC for prolonged times* Air conditioner systems that stay inactive (still holding large amounts of condensed water at the evaporator) in very warm conditions, then are suddenly turned on* Evaporative cooling towers people come in close contact with* Rarely used shower heads in warm bathrooms* Rarely used pipe stubs in large DHW systemsHousehold cases where someone only heat their water to 50degC instead of maybe 55 - I don't believe there are cases at all.Serious cases all share long-term exposure at temperatures around 30-40 degC (optimum for growth) and then something that makes fine mist out of this water so that people breath it in.

author: tom66
author_rank: Super Contributor
timestamp: February 24, 2024, 08:07:52 pm
content: Can legionella even grow in a hot water tank? The majority of modern hot water tanks, at least in the UK, are unvented with external expansion vessels, as this tends to be more efficient. Since the vessel is under pressure, essentially the entire volume is full of water. Legionella is not an anaerobic bacterium, so the chances of the bacteria even having a location in which to grow is questionable. I suppose it would be a concern for a vented system, but in the UK those haven't been installed for 20+ years.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 24, 2024, 08:24:16 pm
content: Quote from: Siwastaja on February 24, 2024, 09:31:32 amEven when I would get a cheap monoblock heat pump and do the work myself and spend say the 4000 euro you mentioned yours costed, it would still take a very long time to see a so called "return on investment" or reach a break even point.What I pay now for my heating is 24m3 of fire wood at 55 euro the m3 is 1320 euro.On average loss of interest on 4000 euro in a savings account lets say 80 euro. (At the moment we get more then 2% here in France, but it will vary)Needed heat energy 16500KWh at SCOP 3.5 is ~4714KWh at an average electricity price of 20 euro cents comes to 942,8 euro.So saving comes down to 1320 - 942,8 - 80 = 297,2 euro per year so comes down to about 13,5 years. At that time it might be needed to buy and install a new heat pump. If not you will have to save up the money you save and it will take another 10 years, with interest on interest, or so to get the initial 4000 euro back in the bank.This is not taking into account the cost of owner ship like maintenance or replacing defective parts if needed, nor is it taking into account the rise in electricity price that comes round once in a while. The latter would also effect the price of fire wood, so not really needed to adjust for.And that is why I said that living costs money.It might be different for others who have much higher heating costs with their current system, but still you will never really get your investment back.To me there is a distinction between saving money and making money. With PV solar panels it might be a different story when you harvest way more energy than you consume and can actually sell the remainder to the energy company. But then still you have to take cost of owner ship into account.

author: Someone
author_rank: Super Contributor
timestamp: February 24, 2024, 08:56:06 pm
content: Quote from: Zero999 on February 24, 2024, 11:20:56 amQuite the reverse from my perspective. You (and others) are jumping onto worldwide generalisations (as applicable to the OP) and arguing (without stating clearly that it only applies to your local situation) that other assessments/positions/choices are wrong....and coming back time and time again without citations, references, or bothering to make basic factual checks on your posts. Oh yeah, thats obnoxious.zilp is putting up some pretty convincing rational arguments for heat pumps even in the UK. Which agree with my simple statements earlier:Quote from: Someone on February 21, 2024, 08:45:49 pmIf gas is so cheap in your market that heat pumps aren't economic for domestic heating, then why isn't someone bottling it up and selling it off to other countries for profit? Why aren't gas power stations running at high utilisation and profiting? Other countries are way ahead on the gas market changing, it's unrealistic to think the UK (or any other country) can maintain such large price ratios on an ongoing basis.

author: tom66
author_rank: Super Contributor
timestamp: February 24, 2024, 08:56:22 pm
content: Quote from: pcprogrammer on February 24, 2024, 08:24:16 pmTrue if you just consider the outright cost of the heat pump, BUT, if you instead install the heat pump when the existing heating system needs refurbishment or replacement (do you have a wood/biomass boiler heating hot water for the house for instance?) then it makes a lot more sense economically since you are just paying the "premium" to get one. Say in my case, a replacement gas boiler costs around £2,500 to have fitted professionally. If I could get a heatpump fitted for about £5,000, then I only have to make up £2,500 in heating costs over a decade, ignoring for now the time value of money. That seems just about feasible - £250 per year in savings (I spend roughly £1,200 a year in gas) or about 20%. If combined with solar/battery and load shifting (not heating the house at peak times and using a tariff that gives me a discount for doing so) then it probably ends up more cost effective.I can get an install for under £5,000 if I use the grant scheme, but the real cost to the taxpayer is another £7,500. Such a system would have a 7 year warranty as long as it is serviced, which is good but not amazing, though better than most gas boilers which tend to have only 2-3 year warranty at best as they are so commoditised now. What worries me is between year 7 - say the end of the life of the system at year 12 if indeed it has failed by then. Do I go for another heat pump? Will costs have fallen by then to be similar to gas boilers? Or will it instead cost £5,000 to have the heat pump unit changed? If that is the case, the economics don't work out against gas.

author: Someone
author_rank: Super Contributor
timestamp: February 24, 2024, 08:59:18 pm
content: Quote from: tom66 on February 24, 2024, 08:07:52 pmStill a problem and while deoxygenation is theoretically possible I've not heard of it being commercially used:https://doi.org/10.3390/w14172644

author: Someone
author_rank: Super Contributor
timestamp: February 24, 2024, 09:18:32 pm
content: Quote from: pcprogrammer on February 24, 2024, 08:24:16 pmWell you did start this thread on the basis that you had to get something to replace the wood burning, or perhaps you'd like to add labour for someone to come and cut/dry/handle/load the wood for you?We've seen this before with people claiming they get their wood for "free" so it's not a cost.... in their shallow analysis."profit" can be real for heat pumps where someone has an ongoing need for some quantity of thermal heating, even if that is immediately replacing or augmenting an existing fully functional heat source. Of course the number varies wildly around the world. What is more common is your situation where a new heater is needed as an existing unit is absent/expired/unserviceable and the choice is now investing one way or another. Higher upfront investment can produce cheaper lifecycle costs, but as you found it needs careful analysis of the available options as salespeople generally only care about their immediate profit while you have some different (varying from person to person) horizon in mind for the investment. Easiest just to state where you want those analysis to sit as you have and then it's clear to everyone!

author: nctnico
author_rank: Super Contributor
timestamp: February 24, 2024, 09:21:38 pm
content: Quote from: pcprogrammer on February 24, 2024, 08:24:16 pmJust out of interest: Are there any ways you could reduce the amount of heat you need without sacrificing comfort?

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 25, 2024, 07:00:25 am
content: Quote from: nctnico on February 24, 2024, 09:21:38 pmNot really as it is already set reasonably low. I'm thinking about heating up more during the night at a reduced rate, but not sure if the offered pump will supply enough energy to reach the needed temperature rise on the coldest days when profit would be biggest.That is part of the experiment.QuoteI never claimed the wood to be free, but do still have about 12m3 from one of our own trees. It was a hell of a job to take it down, partly due to my disease, but also because it was a very big oak tree to close to the house. Cutting up all the branches and the trunk took us weeks. Apart from that labor and the petrol for the chainsaw and electricity for the splicer it is "free" wood.The thread was started to find out if sales people are lying about air to water heat pumps having far worse performance then ground to water heat pumps, and what the noise levels are.And as with everything on the net you have to filter and analyze the given answers to get to the bottom. Conclusion is that the two systems are not far apart and definitely not the factor two that one of the sales people claimed.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 25, 2024, 09:03:16 am
content: Quote from: pcprogrammer on February 24, 2024, 08:24:16 pmYeah. Calculate the cost for maintaining the wood burner and especially the time and effort you need to spend burning wood, and it not only evens out but exceeds that of the heatpump because the monoblock heatpump is nearly maintenance-free. I have had mine running for three years with no maintenance, unless you include the few seconds of my time used to pick a stuck leaf out of the evaporator coil. End-of-life for such heatpumps is typically around 10 - 20 years, maybe 12-15 median. Calculate the savings with a slightly pessimistic 10 years and you won't go too wrong.In your case, you will again reach optimum with a hybrid system (as you don't have to invest in wood burner): burn wood when COP < 2 or so, and this effectively brings the SCOP of the heatpump up, and thus total energy cost down a bit.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 25, 2024, 10:18:55 am
content: Quote from: pcprogrammer on February 25, 2024, 07:00:25 amNow the question really is, do you want to burn the results of your hard work in one winter, or maybe use it in a hybrid solution for the next 5 winters?I started renovation of upstairs by just dismantling everything before putting in new materials, and that produced a few m^3 of 2x4" and 1x5" from 1950's, good untreated wood (spruce most likely). My wife spent a lot of time removing all the nails before I cut it to fixed length pieces. So in the same sense, this is also "free" wood, but carries some emotional attachment.In addition to random sauna use, I have used this wood to heat the house for two winters now and it feels good to use this "waste". If I only heated by wood, it would have been gone in the first winter even before the first seriously cold weeks. During that time, the heatpump on the other hand produced heat with excellent COP and little electricity.Quote from: Someone on February 24, 2024, 09:18:32 pmSalespeople are funny. Expensive turnkey solutions:What salespeople sell to the customer: theoretical savings of the best case installation +30%, payback in 2 yearsHow you are billed: Heavily customized solution tailored for your specific needs, with the best-in-class oversized heatpumpWhat you actually get: underdimensioned, one-size fits all installation, with some unoptimal flaw which wastes half of the savings, payback in 30 years except the pump doesn't last that long.Then again, if you know something about the market and products and how they are useful, you still don't have to DIY, but you have to manage the project. This way cost is less and end result better than with most turn-key solutions.

author: nctnico
author_rank: Super Contributor
timestamp: February 25, 2024, 10:56:27 am
content: Quote from: pcprogrammer on February 25, 2024, 07:00:25 amSorry I wasn't clear, I was hinting at adding insulation so you can reduce the amount of energy going out of the home.

author: tszaboo
author_rank: Super Contributor
timestamp: February 25, 2024, 11:19:56 am
content: Quote from: Siwastaja on February 24, 2024, 08:29:08 amSee, this is what makes sense. Using easy to install technologies to save energy on the existing houses. Building new houses with the new technology in mind. Leveraging technology without bankrupting ourselves.The same way, we don't want to ban spark plugs for cars, just because we want people to switch to electric. And tell people who need a new boiler "just buy electric".If OP installs an air to air heatpump maybe he can reduce the heating season here from 4-5 month to say 2 month. Buy installing heatpump on 2-3 rooms and using it additionally to the heating he has. Save 40-50-60% of the bill (and reduce CO2) with 1/20th the investment.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 25, 2024, 11:52:15 am
content: Quote from: tszaboo on February 25, 2024, 11:19:56 amFair enough, but in specific case of OP, air-to-water heatpump is such easy-to-install retrofit. It's a perfect match because of the existing under-floor and low-temperature radiators. The problem is only navigating past overly expensive turn-key solutions and either do-it-yourself or find the right contractors to do it with sensible cost. Total cost should be only marginally larger than 2-3 room air conditioner units (1000EUR each installed). If price difference is more than 2-3x (let alone 20x as you suggest) then something is wrong and you are not looking hard enough for the right supplier.

author: Zero999
author_rank: Super Contributor
timestamp: February 25, 2024, 12:36:21 pm
content: Quote from: pcprogrammer on February 25, 2024, 07:00:25 amOak is quite expensive. It might have been more economical to sell the wood and use the money to by pellets, or scrap offcuts, than burn that tree!It's not just sales. I don't completely trust everything people say on forums such as these, when it comes to heat pumps, because it has the potential to be shaped by ones political stance. I'm not accusing anyone of lying, just bias, which many people are unaware off. This is true for both those who are strong advocates, as those who are against. Another thing is everyone's usage and climate is different.It's very difficult to find objective data. Not only does COP, of an air source heat pump, depend on the inside and outside temperatures, but also the relative humidity.I had a bit of a Google and found lots of contradictory information.This laboratory test shows a COP of between 3 and 5, at 5°C, but it was done under very dry conditions. I live in a very humid climate and COP does down with high relative humidity, when the air temperature is 5°C.https://www.nrel.gov/docs/fy23osti/85081.pdfThis Italian study is probably more relevant, as inland areas of Northern Italy have similar winter temperatures and relative humidity as Southern England. The downside is it's over ten years old and heat pump efficiency might have improved since then.https://www.sciencedirect.com/science/article/pii/S187661021400071X?ref=pdf_download&fr=RR-2&rr=85afe559b8a379b5A quote which I find concerning.QuoteGiven this can I trust data based on European standards, or is this not the case and this is out of date information?This one from Strathclyde shows slightly lower COPs.https://www.esru.strath.ac.uk/EandE/Web_sites/10-11/ASHP_CO2/ccl-potential.htmlSomeone on a British forum complaining about a COP of 2.3 for space heating and 2.5 for water.https://forum.buildhub.org.uk/topic/34775-is-my-cop-rubbish/I think those who estimated a COP of 3.5 for me were optimistic. 2.5 seems more likely, given the data I've seen.I've also realised I didn't take into account the fact that if I can stop using gas, which would also involve replacing my cooker with an induction hob, I can reduce my standing charge (a flat rate daily connection fee, which independent of usage), but then I have to factor in the fact it probably costs a bit more to run.

author: tszaboo
author_rank: Super Contributor
timestamp: February 25, 2024, 02:14:13 pm
content: Quote from: Siwastaja on February 25, 2024, 11:52:15 am"Should be" is a keyword. It's not.I've quickly looked up air to hot water pumps, they start at 3500. You get a subsidy, but only if they install it.

author: nctnico
author_rank: Super Contributor
timestamp: February 25, 2024, 02:49:30 pm
content: Quote from: Zero999 on February 25, 2024, 12:36:21 pmIn the end nothing beats getting information about hands-on experiences with the equipment. On a forum you can get a good list with prospects with some pros & cons but from there you have to start reading reviews about the various pieces of equipment out there. A good source may be looking for a forum where installers of heatpump systems hang out (likely a forum for AC installers as these are related) to get some info about maintenance problems for various models / brands.

author: zilp
author_rank: Frequent Contributor
timestamp: February 25, 2024, 02:53:06 pm
content: Quote from: Zero999 on February 25, 2024, 12:36:21 pmThe funny thing is that the effect of humidity is actually both beneficial and detrimental. On the one hand, there is a lot of latent energy to be had from condensing water vapor. On the other hand, if you get to the freezing point at the evaporator surface, the condensed water freezes and clogs up the evaporator, requiring energy to be expended for defrosting. Though it should be noted that the phase transition from liquid to frozen also releases latent energy, so the energy "spent" for thawing the ice was previously extracted from the ice by the heat pump. It's just that the heat pump will release more energy than would be absolutely necessary for thawing the ice, and also, the heat might be taken from a different place than where the extracted energy was pumped, both of which will generally make the freeze/defrost cycle a net energy loss and thus reduce COP. This is probably the primary thing that reduces COP around the freezing point with high humidity.Quote from: Zero999 on February 25, 2024, 12:36:21 pmI have no idea as to the current requirements in the relevant standards, but I guess it isn't really possible to specify a representative way to include defrost energy in one generic COP number, as that, as you yourself said, depends on humidity, and also on rather specific weather patterns. Specifically: It's not something that is well captured by average values, because the COP (including defrost energy) will often be better at -5°C than at +3°C at the same relative humidity, so, the amount of time during a year spent in the critical region determines the influence of defrosting on COP.At the same time, more transparency wrt defrost energy certainly would be useful, because there certainly is optimization potential. My own heat pump, for example, defaults to defrosting with a resistive heater. Or more specifically, it takes heat from the storage tank (that's kept at DHW temperatures) for defrosting, but switches on the resistive heater in the tank during the process to re-add the energy it extracts from the tank during defrost. But you can just disable the resistive heater and it will happily take the heat from the tank anyway, which was pumped there at a COP of ~ 2 or so (during winter), thus halving the electricity used for defrosting. (You just have to manually re-enable the resistive heater when it is actually needed, which obviously wouldn't be necessary if the controller were just smart enough to do this automatically ...)Equally, COP doesn't reflect standby consumption of the heating system. My own heat pump uses 12 W in standby, i.e., all pumps off, compressor off, just watching tank and room temperature, eats 100 kWh in a year. Obviously, that should be possible at sub 1 W, right? Given that the system sits idle ~ 70% of the year ... that should be an easy improvement to make for a ~ 3% reduction in power consumption, shouldn't it?Quote from: Zero999 on February 25, 2024, 12:36:21 pmWell, did you read the thread?During the time apparently covered by those numbers, they had huge holes in the wall, the flow sensor was broken, the total thermal energy they report is significantly lower than what they used in previous years (which might well be because of the broken flow sensor), ... i.e., for all we can tell, that COP is just complete nonsense?Quote from: Zero999 on February 25, 2024, 12:36:21 pmI don't think anyone estimated a COPfor you? Obviously, noone here knows the specifics of your heating system, so it would be nonsensical to estimate a COP for you based on no information. The 350% mentioned by me and others is a good general assumption about heat pumps on average, i.e., a useful basis for discussing, say, general policies as to how to switch energy supply of a country to renewable energy. But obviously, it would be nonsensical to use such a general average to make investment decisions for a specific house. And it is equally nonsensical for you to just assume 250% instead. 350% is fine for a first back-of-the-envelope calculation. Beyond that, you need to measure the actual properties of your heating systems and look at the COP curves published by heat pump manufacturers to get a reasonably accurate estimate as to what you could achieve with a particular heat pump model in your particular home.Quote from: Zero999 on February 25, 2024, 12:36:21 pmChances are it doesn't. Gas stoves are very inefficient as far as heating the stuff you put on them is concerned, they primarily heat the room they are in. Whether that's a loss obviously depends. If you are at the same time heating with gas anyhow ... well, you might as well burn it in an open flame in the kitchen? Though the increased CO (and CO2) concentration might be a reason to open the window, so maybe it's net negative still. But then, during summer, you might increase cooling load and thus pay more for getting rid of the waste heat than you saved from the cheap-ish energy source. Or at least it might make things more uncomfortable if it is too hot for your comfort already.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 25, 2024, 03:32:37 pm
content: Quote from: Siwastaja on February 25, 2024, 10:18:55 amWe have a small wood burner in the kitchen/living that is going to consume that wood. That space has to much volume to be heated with only the underfloor heating also due to the chestnut floor we have on top of it. Ceramic floor tiles would have been better, but we like the wooden floor.Inexperience with underfloor heating when designing the system made this happen. Should have added some radiators, but in stead there is the wood burner to lift it from ~17 to >20.QuoteOnly when you buy it as ready made planks from a DIY store.No sawmill owner over here will come to only take a single oak tree.

author: jmelson
author_rank: Super Contributor
timestamp: February 25, 2024, 04:10:50 pm
content: Quote from: pcprogrammer on February 25, 2024, 07:00:25 amMany years ago my wife had a house that had an air to air heat pump. It also was a "brick frame" house, not "brick veneer", meaning the walls were a single course of bricks with no air space or insulation from exterior to interior. It had tons of insulation in the attic, but that was pretty useless. In the moderate winter climate of Missouri, the place was impossible to heat!Where we live now, some neighbors have air-air heat pumps. When I am outside near their property, I can hear the unit running, and hear the valves changing over for defrost, but it is no louder than a typical air conditioner. But, NO QUESTION, a ground-source heat pump will do the job on 1/10th the energy. A friend did have a modern log cabin out in the woods with a ground source heat pump, and he used to brag about the CRAZY low energy bills!Jon

author: Siwastaja
author_rank: Super Contributor
timestamp: February 25, 2024, 07:08:49 pm
content: Quote from: tszaboo on February 25, 2024, 02:14:13 pmBut 3500 is not that much at all IMHO. Sure I'd like to see them start at 2000, but. 3500EUR is quite easily recovered already during halfway of the lifetime of the product. It gets nasty when the heatpump is 7000 (some sort of premium brand name which isn't that much better in reality) and then the install cost another 7000, or even more.

author: Zero999
author_rank: Super Contributor
timestamp: February 25, 2024, 07:30:56 pm
content: Quote from: zilp on February 25, 2024, 02:53:06 pmGoing from what I've read, humidity can both increase, as well as decrease the COP. If the temperature is above 6°C, high humidity generally increases the COP. At temperatures below 6°C, high humidity deceases the COP, which is worse around freezing, then becomes less of an issue below freezing, since freezing air holds less moisture.In my specific situation, I expect the heat pump to mostly run when the temperature is around 0°C to 6°C, hence why I believe the humid climate where I live is a hindrance, rather than a help. If I were going to use it for hot water, say to heat a pool in summer, then it would be different.QuoteI understand that it's not a simple calculation. It's similar to car mileage, in that it depends on how it's being used.Yes, your standby consumption does sound high. I would have hoped that minimising it would have been an important design goal.QuoteTo be honest, no I didn't read the whole thread in detail. I concentrated my efforts on reading objective studies. Whilst forums can be useful and a lot can be learned from them, much of it is anecdotal. The only reason why it caught my attention was the numbers were similar to studies in areas with a similar winter climate, to where I live.QuoteI thought reading objective studies about heat pumps in areas with a similar winter climate, to my location would give me a reasonable figure. I accept that it will be different, depending on how I use the heat pump, but I would have thought it would by closer, than a general ballpark of 350%, which doesn't even take into account the local climate.I'm not sure how much I trust COP figures given by manufactures, given there are numerous different factors and they are likely to be skewed in the manufacture's favour. I've seen this with component data sheets, audio amplifiers and vehicle mileage, although I've also had instances when it's better than expected, such as my motorcycle doing more miles per tank, than expected. I suppose I'm more careful, because it would be a big investment, it's not something I'm overly familiar with and then there's the political side to it, which doesn't help.QuoteI'm aware of the fact that gas stoves aren't very efficient, I've read 40% is reasonable, but don't forget electricity costs four times as much for me, as gas, so an induction hob will still be more expensive for me to run. I doubt it will make much of a difference since, only a tiny part of my energy usage is for cooking, but it's something to consider.I doubt it'll make any difference to ventilation. I have a CO detector, which never goes off and I only use the fume extractor when I'm cooking something smelly.I generally avoid cooking in hot whether and summer is generally cool where I live, so unwanted heat is less of a big deal.Quote from: Siwastaja on February 25, 2024, 07:08:49 pmI agree. That doesn't sound expensive for the heat pump itself. It's the rest of the installation and associated labour which is expensive. Subsidies are only given if you use an approved contractor and it has to meet certain criteria. I don't even know if it's legal for you to do it yourself. I would expect a licenced refrigeration tech will be required, or at the very least an electrician with the appropriate qualifications.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 25, 2024, 07:38:25 pm
content: Quote from: Zero999 on February 25, 2024, 12:36:21 pmI agree the information is not that easy to find. You need to combine bits and pieces and measurements by individuals. One helpful advice that I have repeated and do it once again: differences between heatpumps (cheap vs. premium) are surprisingly small, and effect of condensing temperature (i.e., water temperature you need to get into your radiators/floor circuits/etc.) is just massive, regardless of brand. Therefore, while we roughly know the climate you live in, not knowing your water distribution temperature, we can't say whether your SCOP will be 2.0 or 5.0. Very unlikely anything outside this range. Maybe you have underfloor heating pipes and good insulation and need water temperature of +27degC. Then your SCOP can easily be 5.0. Maybe you have tiny radiators that act as the name suggest, primarily radiating the heat instead of natural convection, and maybe you need +80degC water to feel warm. Then SCOP would plummet to 2.0 or so, as you would run on resistive aux heating at COP=1, large part of the winter.Then again, if you read a complaint that COP is bad when one has a massive hole in the wall and they are producing steaming hot water at full power 24/7 during winter, I would just ignore the whole discussion and try to find more useful data points. Unless, of course, you have a large hole in your wall, too.QuoteI can say from own experience that COP most definitely goesupin high humidity conditions when the air temperature is +5°C. You can easily see this from the fact that Tpipe (evaporator internal temperature) as measured by the heatpump is closer to ambient temperature in such conditions (e.g.: dry air, Ta=5.0, Tpipe=-0.5, ice is forming; RH=100% humid conditions: Ta=5.0, Tpipe=3.0, it rains under the outdoor unit).More heat can be extracted because turning water vapor into liquid releases a lot of latent heat. At +2 or so things get different - even the high humidity is not able to keep dT low enough, and freezing will start to occur. At medium humidity, freezing can occur already at +5 or so.Defrosting is fundamentally not a bad thing: if you calculate the total enthalpy you are seeing the sum is actuallybetterthan in completely dry lab conditions! You get extra heat by making ice from water vapor in the first place, and during defrost you don't turn it back to vapor, mostly liquid, so you gained more than lost! In reality of course significant losses are involved, e.g. because the compressor is used to transfer the heat round-trip, and because, even with fan stopped, the evaporator (now condenser during defrost) sits hot in the outdoors air, possibly in windy conditions, for a minute or two, so defrosting reduces true COP below the level of dry testing, but given decently working decision algorithms (which they usually are), the effect is much smaller than many assume.Specifically air-to-water units are very efficient at defrosting because they have better source of stored heat, in form of hundreds of liters of warm water, than air-to-air units which can only utilize the tiny amount of thermal energy stored in the indoor unit coil (copper with aluminum fins) and therefore heat the outdoor unit with worse COP during defrost. This is easy to see from the power consumption of e.g. my heatpump, which, for the 2300W input power unit, is just between 300-600W during defrost, and it only lasts for 3-5 minutes.But sure, there is a small dent in COP curve around +5degC. It doesn't get progressively worse, as very cold air will be dry. The loss for every defrost cycle is higher when very cold, but fewer are needed, so there is just a small jump of about -0.2..-0.3 near +5degC compared to dry testing which keeps quite constant down to however low temperatures.QuoteYou can keep being a concerned citizen, but then again, this is how reality works. Your car consumes more fuel than the official numbers, just like every other car in existence, and just like they always did. Your condensing boiler performs worse compared to marketing material, I'm 100% sure about that. This is human nature. The big question is, are you making sensible decisions based on best effort of obtaining true data, or just using your concerns and uncertainties as coping mechanism?QuoteSCOP of 2.5 in British weather, which is pretty optimal for air source heatpumping (at least from Finnish perspective), would require some massive blunder. It's not impossible to do that badly, but it would be an outlier. I'm close to 2.5 (don't have exact measurement but very good guesstimates) in Finnish climate which is significantly colder.However, important fundamental fact to understand is that COP is not a constant over year. We talk about annual COP, SCOP, defined simply as annually produced thermal energy divided by annually consumed electricity. We do this because we are interested about how much money we are putting in the long run. Heatpumps are not suitable for those who only have £100 on their bank account and are struggling to pay a single bill on February, because of the cost nonlinearity, which makes the effect of time-of-the-year on the bill even larger than it already is with linear systems (basically everything else than heatpumps).QuoteThis is indeed another (albeit small) downside in gas-based systems, you rely on another contract and someone supplying you with this product every day. Compare with wood or oil (I use both as auxiliary heating methods) which can be locally stored for years, and if you mainly do heatpump, the volumes that need to be stored are modest.

author: Marco
author_rank: Super Contributor
timestamp: February 25, 2024, 08:34:22 pm
content: Wood is clearly the cheapest per kwh if you have the space to have ton's worth delivered by truck.Though on truly modern homes so little heating is required that it would almost never be worth the effort unless you enjoy fuelling the stove.

author: nctnico
author_rank: Super Contributor
timestamp: February 25, 2024, 08:47:34 pm
content: Quote from: Zero999 on February 25, 2024, 07:30:56 pmThe nameplate COP / SCOP number is a standarised value at a standard indoor / output temperature. However, there should be more detailed information available. The service manual for the Panasonic airco unit I have, has extensive tables that show COP/SCOP for combinations of indoor / outdoor temperatures.

author: Zero999
author_rank: Super Contributor
timestamp: February 25, 2024, 09:28:52 pm
content: Quote from: Siwastaja on February 25, 2024, 07:38:25 pmYou raise some interesting points, but I won't quote everyone of them and reply to save space. Note that just because I've not responded to and quoted them all, it doesn't mean they were unhelpful or that I have ignored them.I know for certain that my current heating system is completely incomputable with a heat pump. The pipes are too thin and radiators too small. The whole lot will need to be replaced, which will be very costly. Although I don't use hot water myself, I still need the option, for when I have guests over and no one else would buy the house, which doesn't have hot water. At the moment it's heated on demand, by the boiler. A heat pump would require a tank and associated plumbing, which would be expensive. I haven't looked at how much it would cost, but I've seen £12 000 mentioned in this thread.To put it into perspective, my energy bill both gas and electricity last year was £545.30. I used 1472kWh in total (including both gas and electricity) last year. Most of my bill is standing charges at £253.78.Regarding the hole in wall comment, no I don't take that forum thread too seriously. I do add more weight to the other articles I linked, which involve real data from Scotland and Northern Italy, especially the latter which is very comprehensive.QuoteA coping mechanism for what?Given the high upfront cost of replacing my current system, which works perfectly, it's perfectly reasonable I'm going to be overly cautious, especially given it's possible the new system won't necessarily be cheaper to run or more reliable, than the current one. This is why it's just a thought experiment at this stage and I have no intention of changing. I wouldn't expect someone to buy a new car, when their current one works fine. I don't see why this is any different.

author: zilp
author_rank: Frequent Contributor
timestamp: February 26, 2024, 12:34:39 am
content: Quote from: Zero999 on February 25, 2024, 07:30:56 pmThe point is that COP doesn't get magically worse around 6°C, COP gets worse due to freezing. Or more accurately, COP gets worse with lower outdoor temperature, but the dip somewhere around 6°C is due to freezing and the required defrost.Which also means that this is not somehow specifically at a magic 6°C, but rather at whatever outdoor temperature that happens to cause the evaporator surface temperature to dip below the freezing point of water. Which depends on, among other things, the thermal power that you are extracting from the evaporator. And on the amount of air being blown through the evaporator. And on the geometry of the evaporator. And who knows what.So, it is possible that you might be seeing defrost cycles at 6°C with some heat pumps in some setups. But really, you mostly shouldn't, because the heat pump will generally be dimensioned for sufficient thermal power to keep your house warm (without resistive heating) at -15°C or whatever (depends on your location, obviously), so the thermal power you are drawing from the evaporator at +6°C (assuming a modulating/inverter heat pump) should be relatively low and should not be sufficient to pull it to below 0°C, especially not with humid air that provides significantly more heat per volume than dry air would.Here, we had rainy wheather and temperatures in the 4 to 8°C range the last few days, but effectively no defrost. I say "effectively" because the controller does a defrost cycle shortly after startup at outdoor temperatures around ~ 5°C or lower (no clue what the exact decision criteria are), but then it keeps going 8 hours or whatever without any further defrosting, until it shuts off because the target temperature was reached, and the ~ 250 Wh of heat it dumps into the evaporator for that don't matter all that much overall (especially given that it probably recovers a significant part of that). (And also, there really is no ice forming, so it's not like COP is dropping but the controller just fails to do a defrost cycle.)Around 3°C with humid air is where things get into terrible territory here, i.e., where you get ~ hourly defrosting.Quote from: Zero999 on February 25, 2024, 07:30:56 pmI mean, it's certainly not ideal, but I suspect it wouldn't be quite as bad as you are imagining it. But if you were to ever go that route, it certainly would make sense to see whether you can set it up such that the heat pump can extract the heat for defrosting from your house. As mentioned, mine pulls from the DHW temperature storage tank, and even defaults to resistive heat for defrost, which is kinda bad. But at higher heating water temperatures, it could potentially also pull from under-floor heating, for example. Some other heat pumps can also do so at lower temperatures. There will always be some cut-off, because a source with insufficient thermal power would risk freezing up and thus damaging the refrigerant/water heat exchanger, but if you somehow can arrange for defrost energy to be pulled from some low-ish temperature thermal mass in your heating system, then that is the most efficient way to go.Quote from: Zero999 on February 25, 2024, 07:30:56 pmWell, yeah, the thing has two separate transformer-based (i.e., mains frequency transformers) power supplies. That seems to be the result of the thing being a bit of Frankenstein's monster built from the heating controller of an old German manufacturer of heating systems and the actual heat pump from Daikin. Certainly doesn't help with efficiency ...Quote from: Zero999 on February 25, 2024, 07:30:56 pmWell, the problem is that the required heating water temperatures have a significant effect on efficiency. And the 350% does take "local" climate into account. Being more accurate wrt local climate doesn't really help much if the details of the heating system remain a variable with a lot of potential variability.Quote from: Zero999 on February 25, 2024, 07:30:56 pmWhat I am talking about here are detailed tables or graphs that specify COP at specific outdoor and heating water temperatures, not something like yearly averages. Just as with specs in component datasheets: They tend not to be outright lies, they just tend to be measured under ideal circumstances, or typical rather than worst case, that sort of stuff. So, a Vf of 0.2 V on the title page of a data sheet might be for 10 mA for a 2 A diode, say. But the Vf vs. I graph won't be completely made-up bullshit. And the same seems to apply for heat pump specs.Quote from: Zero999 on February 25, 2024, 07:30:56 pmYeah, my point was more that it's not worth the base fees to keep cheap gas for cooking, and that the advantage probably isn't huge. And 40% might be a bit optimistic, but it's the right ball park.Quote from: Zero999 on February 25, 2024, 07:30:56 pmIIRC, Siwastaja was talking about a monoblock system, so the refrigerant loop is a closed system within the outdoor unit and only electricity and water need to be hooked up, which is why you in most places don't need a licenced refrigeration tech, which is why they are popular with DIYers.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 26, 2024, 07:24:33 am
content: Quote from: Marco on February 25, 2024, 08:34:22 pmMaybe / possibly somewhere, but I'd say usually not.Fun fact: two years ago due to events that did not actually affect Finland that much in any meaningful way, people got hysteric and got animpressionthat cost of electricitywouldskyrocket to 2x, 3x, 5x, 10x, 20x, whatever insane value. Mass media poured buckets of gasoline into the fire. A few were gullible enough to get colossally expensive 2-year fixed contracts in irrational fears of increasing prices which never happened, but this con did not affect the majority of people.Inrealityelectricity prices rose by 25% (typicalcost; energy 0.05€ --> 0.08€ /kWh, transmission+tax 0.07€ --> 0.07€, total 0.012€ --> 0.015€), but those selling wood, mainly small individuals who own some forest, in a cascading effect took advantage of theimpressionof expensive electricity so that m^3 of wood (around 1000 kWh including typical losses) went from like 30-40€ to well over 100€. So the individuals who criticize large corporations from causing greedflation by increasing prices by 10% for no reason themselves increased prices by 200% almost overnight without blink of an eye.But it's free market, sure. In some cases, burning wood became more expensive than resistive electric heating with COP=1. Wood transitioned from the "cheapest" form of heating to the most expensive one!In mid-European climate though, heatpumps easily get COP between 3.0 and 5.0, so electricity needs to be specially expensive, or wood specially cheap for wood to be "clearly the cheapest".

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 26, 2024, 07:43:33 am
content: Quote from: Marco on February 25, 2024, 08:34:22 pmOnly if you can source it cheaply, and in the Netherlands you most likely can't.It also involves a lot of work. The truck load is usually dumped somewhere accessible and not necessarily near the space where it is stocked. So wheelbarrow to the stocking is needed and when the time comes you have to bring it inside to the burner. For sure it keeps you warm multiple times.I know someone who bought a truck load of of-cuts from a barrel maker down here and transported it to the Netherlands to sell it with quite a bit of profit.

author: tszaboo
author_rank: Super Contributor
timestamp: February 26, 2024, 10:14:12 am
content: Quote from: Zero999 on February 25, 2024, 07:30:56 pmKeep in mind this is the cheapest I was to find in a particular Dutch webshop. Let's assume the installation costs and the subsidies cancel each other out. The installation is relatively painless compared to exchanging the entire heating system. Then we are at 3500 EUR investment which is only for hot water, not for heating. Upon double checking the shop, it's not on stock, might be one of those things that is never on stock to just get your attention with good price. Anyway, let's move on.I take my summer hot water costs, it's 0.5GJ/month/person. Which is billed for me at 22EUR, excluding the fixed costs. And that's 140KWh per month energy. The same would cost me 56 EUR with direct electric heating (0.4EUR/kWh). District heating is incredibly expensive because of bad regulations here, and the monopoly, but that's just a sidenote.Let's assume SCOP of 5 which would put this at 12 EUR/month, saving of 10 EUR per month. That would place it at 30 year ROI. For 4 person, 7.5 year ROI. This is, if I have to buy the electricity.If I can use my own electricity to heat it up, the story changes. I can oversize my solar system by 1500KWh per year, which is about 1000 EUR investment here. About 2-3 panels will do that much. We have to assume yearly net metering for this to work. Then The investment is 4500 EUR, and the monthly saving is 22 EUR. ROI is 17 year for one person, 10 year for 2, 6 years for 4 person. That also assumes that you can place an extra 6000KWh/year solar capacity on your roof, that's about 11 panels here. That's assuming that the cheapest heatpump will even suffice for a family of 4, looking at the supplied tank size, I don't think so, it's tiny compared to what I've seen. And it's capacity is only 5kW. Net metering is also being phased out. The regulation around district heating is changing, so I expect much lower prices next years.So I only see this to be valuable for large families.Quote from: pcprogrammer on February 26, 2024, 07:43:33 amYeah someone in the neighborhood was buying wood for cooking in the garden and that sort of things, and I was seriously questioning his sanity when he told me how much it cost. I think there is an issue when people are just uninformed how much something should cost, and companies are praying on us with extra profit. The good prices are not easily accessible. That's why we have internet at 70 EUR a month, while the same speed and accessibility, costs less than 20 in other countries.

author: tom66
author_rank: Super Contributor
timestamp: February 26, 2024, 10:38:35 am
content: A monobloc can be installed by someone without a refrigerated gas (F-Gas) license in the UK because the system is 'pre-gassed' -- only hot water passes out of the unit. There are other types of air conditioners which can be installed by people without F-Gas certification, like propane based mini-splits as propane has a GWP of 3 and ODP of 0 so its release into the atmosphere is not considered particularly hazardous.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 26, 2024, 11:58:54 am
content: Quote from: tszaboo on February 26, 2024, 10:14:12 amNormally, sensible people would get air-to-water heatpump to heat both the house, and DHW. For hot water only, quite obviously it will not make any sense, unless you are running a public bath.

author: NiHaoMike
author_rank: Super Contributor
timestamp: February 26, 2024, 12:14:56 pm
content: Quote from: tszaboo on February 26, 2024, 10:14:12 amWood for cooking is often for a specific flavor, that factor alone makes the specific kind of wood far more expensive than general purpose firewood.Quote from: Siwastaja on February 26, 2024, 11:58:54 amFor just hot water, a much smaller and cheaper heat pump will do.

author: tszaboo
author_rank: Super Contributor
timestamp: February 26, 2024, 12:24:07 pm
content: Quote from: Siwastaja on February 26, 2024, 11:58:54 amWe already talked about that. That starts at 12K for the equipment, new floor, new paint + finish for the walls, several months installation time, entirely new heating system. That ballpark 50K, not 3.5K. The one for 3.5K doesn't even support heating.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 26, 2024, 01:15:33 pm
content: Quote from: tszaboo on February 26, 2024, 12:24:07 pmThis is one weird discussion. One caneasilymiss the fact that you are here just trolling, and accidentally take you seriously, like I did. It is unfruitful to discuss a case where a product which is completely unsuitable for your use case and just throw around ridiculous numbers when you force-fit it. Why stop at 50k, why not ten thousand million trillion billion? In reality, you just should do something else and not even consider air-to-water heatpump for your case.People usually assume you are being sensible and honest, and don't want to read tens of pages of wall-of-text to find something that shows you were not. From now on, you are ignored by me on this thread so the mistake won't happen again.

author: coppice
author_rank: Super Contributor
timestamp: February 26, 2024, 01:39:18 pm
content: Quote from: NiHaoMike on February 26, 2024, 12:14:56 pmThis can be true, but it often feels like they are using the most bizarre wood for no good reason. Like the use of mesquite for barbeques in Arizona. Mesquite is a tree that grows in the desert, and has very dense hard wood. Growing in the desert, you can imagine how long it takes to grow big enough to be harvested, and tossed on the fire.

author: peter-h
author_rank: Super Contributor
timestamp: February 26, 2024, 04:28:48 pm
content: I have not read the whole thread but here is my two cents based on seeing many installations, and running my own air to water one.The claimed COP turns to ***t in conditions where evaporator icing is possible, which is basically anytime the humidity is above about 50%, which is most of the timeThe pump then has to go into reverse cycle to thaw it, which is ridiculous.The COP is poor in ambient temp anywhere near 0C.The output temp is not great (thermodynamically, pushing heat up the hill is hard) so you really need underfloor heating. Radiators need to be pretty large otherwise and here in the UK you can forget it if you want to achieve +21C inside with -8C outside, with radiators.Heat pumps work great with a ground source (borehole, or a long buried pipe) but you still want underfloor heating.Having it outdoors corrodes it nicely and produces a fairly short life (under 10 years). This is again where ground source is good because the pump is naturally indoors.The bigger ones, say over 5kW claimed output, are better (more reliable) with a 3 phase compressor.

author: nctnico
author_rank: Super Contributor
timestamp: February 26, 2024, 04:43:32 pm
content: Quote from: Siwastaja on February 26, 2024, 01:15:33 pmTrue. You have to keep in mind though that 'something else' is easier said than done. In the NL a large number of people are stuck with homes which are not suitable for any kind of heatpump because the insulation is insufficient and it is financially not viable to upgrade the home as it would come down to rebuilding the home from scratch. The only alternatives there are to replace natural gas, are district heating or hydrogen (as a replacement for natural gas).

author: Siwastaja
author_rank: Super Contributor
timestamp: February 26, 2024, 05:14:06 pm
content: Quote from: peter-h on February 26, 2024, 04:28:48 pmThis is weird, because just today we have witnessed some very British weather: the whole day has been +1degC and RH exactly 100% + thick fog.Number of defrost cycles between 7am and 7pm (right now) is:2. For example, the previous run cycle:Started at 15:32Defrosted at 17:06Finished defrosting at 17:11Running at minimum power, reached upper temperature setpoint at 18:01 and stoppedThere is nothing "ridiculous" in defrosting. It's completely normal, it's a feature, not a bug. Did you actuallymeasureor otherwise verify it's causing a problem? Or do you just "feel" it is "ridiculous"?During the last 24 hours, 19.136kWh has been consumed by the heatpump. The heat as required by the house, to maintain +22degC indoors, at this weather, is approximately 50kWh/24hrs based on earlier calculations and tests. Additionally, the heatpump pre-heats domestic hot water, amount of which is hard to exactly say, but we have a 1.5 year old poo generator who needs butt washing and stuff like that, so with two showers, some dishwashing etc. I would quickly guesstimate at least 10kWh worth of hot water preheating took place. Therefore, COP would be around 60kWh/19.1kWh = 3.14.Manufacturer test reports, which honestly says it ignores defrosting, and thus probably also ignores the bottom tray heater, and which also ignores water pump, which I do include in my numbers, states COP = 3.95 in similar conditions. Once you add water pump, it's down to 3.55. Once you add bottom tray heater, it's down to 3.09, nearly exact match with my estimate. This means the heatpump is doing excellent job with defrosts ending up with the same COP than in dry tests (which is unsurprising, if you read my previous longer post about it); and one could improve the heatpump, not by magically removing need for defrosting by dehumidifying the whole planet, nor by improving defrosting decision algorithms,but by more intelligently controlling the bottom tray heater, which is something I haven't done yet; I have not modified the thing at all.Does your system work, and have you measured the consumption to verify there is a problem? Or is this again some feeling mumbo jumbo?QuoteAlso this is obvious bullshit, there is nothing special in UK climate at -8C compared to e.g. Finnish climate at -8C, RH varies between 85-100% anyway at that point. -8C and +21C is completely normal everyday operating point for me, and yes, with radiators, albeit admittedly swapped for larger sizes than original.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 26, 2024, 05:17:37 pm
content: Quote from: nctnico on February 26, 2024, 04:43:32 pmAir source heatpumps are quite acceptable for poorly insulated houses, they are e.g. used in traditional Japanese houses basically made out of thin wood frame and paper. You just keep the thing switched off when not present, and turn it on when you are there. It blows warm air towards you and heats up the air in the room pretty quickly. COP is very good because the condenser can run at low temperature, especially when you coldstart the heating. Of course a lot of energy is wasted with poor insulation, but this is wasted with any form of heating and therefore high COP is of high importance.Ground source or air-to-water heatpumps indeed do not work too well (this is probably what you mean) in such cases unless you install water fan coil units, replicating the behavior of the simple air-to-air units for much higher cost; if there are radiators at all in such poorly insulated houses, they require high temperatures that can be only provided by burning something in a boiler.

author: tszaboo
author_rank: Super Contributor
timestamp: February 26, 2024, 05:34:12 pm
content: Quote from: Siwastaja on February 26, 2024, 01:15:33 pmAre you serious? Let's just take a ballpark installation for a 120 sqm house. I'm going to look up prices for you. New floor, 40EUR/SQM, installation costs 10-20 EUR depending where, let's cut the middle at 15 EUR/SQM. So floor is 6600 EUR. Painting the entire house, 2-3 days of work for 2 people, 3000 EUR. Pray that you don't need a new kitchen.Floor heating installation cost: 7800EUR +2500EURhttps://www.reddit.com/r/Netherlands/comments/18mrkba/under_floor_heating_cost/Disconnecting district heating: 4200 EUR (Not a joke)Removing every furniture, storage for the duration of the work, moving back: 2x1500 EUR for moving, Storage few hundred EUR. Again, pray that SO doesn't get creative and decides to buy new furniture.Actual heat pump 9500 EUR. You get back 20-30% as subsidy. Juppy je, that's as much as the VAT. :https://www.klimate.nl/panasonic-kit-wxc09h3e8-lucht-water-warmtepomp-singlesplit.htmlHeatpump installation cost: 2300EUR.https://cv-kosten.nl/warmtepomp/(De prijsopbouw van de installatie van je warmtepomp)Again, going with my neighbor's example, if you are lucky, you can organize the entire thing in two months time. Because their agenda is usually completely full.Total listed here was 36000 EUR. You know what, it's not 50000 EUR, though I probably left out a few things. That calculation was for the ground source heatpump.And no, I cannot "just install larger radiators", they are sized for 70-80C district heating, and it's completely unsuitable for low temperature heatpumps.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 26, 2024, 05:42:51 pm
content: Quote from: tszaboo on February 26, 2024, 05:34:12 pmYes yes yes, we heard you already, your house is not suitable for air-to-water heatpump retrofit, we got it. I could come up with a calculation how expensive it would be to run natural gas heating on the Moon, including the work to build a pipeline from NL to the Moon, and then just throw around the number of ten gazillion megagillions in every thread, but I prefer not to. Now please can you just go away wasting our time, thank you.

author: tszaboo
author_rank: Super Contributor
timestamp: February 26, 2024, 06:12:13 pm
content: Quote from: Siwastaja on February 26, 2024, 05:42:51 pmYes, because brushing off issues like the OP's issue (who is btw from the Netherlands) is the right solution. And houses are built everywhere like the Finnish standard, because we all get -40C in the winter. But that's ok, because you can just tell everyone that it's only 500 EUR. One size fits all!

author: Siwastaja
author_rank: Super Contributor
timestamp: February 26, 2024, 06:21:16 pm
content: Quote from: tszaboo on February 26, 2024, 06:12:13 pm.. whose house is in France and it DOES have underfloor heating lack of which you are complaining about so your game is now exposed, you did not care about helping the OP the slightest bit, you did not even read any of the OP's posts unlike me and others. You are here just trolling and spoon feeding your own case disguised as some sort of advice for others. Now enjoy the actual ignore list because it seems I can't resist replying to dishonest people like you.

author: nctnico
author_rank: Super Contributor
timestamp: February 26, 2024, 06:42:18 pm
content: Quote from: Siwastaja on February 26, 2024, 05:17:37 pmThat is not going to work. One of the reasons you really need to heat a home thouroughly is to keep moisture under control to avoid issues with mold.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 26, 2024, 07:30:04 pm
content: Quote from: nctnico on February 26, 2024, 06:42:18 pmIt is not "going" anything, it is how millions and millions of people actually live. Complete shutdown of heating is maybe a slight exaggeration, but the level is definitely adjusted based on being present or not, and poorly insulated houses with little thermal mass cool down and heat up quickly. Remember, when people are not present, also water vapor is not being produced by breathing etc. And these poorly insulated houses are not also very windproof, so they naturally ventilate. For mold control anyway fairly small temperature differences are sufficient, such as 5-6degC as studied at Tampere University of Technology where I attended too, so if it's say 0degC outdoors you don't need to heat to +20 to keep the mold out. All that is needed is to reduce RH% to somewhere below 75% and that happens with a few degrees of difference under all conditions. "Keep dry" systems are basically constant power heaters.This style of living is unintuitive for those who are used to having more thermal mass and good insulation - and heating which is kept to provide constant temperature. Also the control strategies to produce savings are totally different. We can easily cut the whole heating for 2-3 hours without much effect on room temperature here for savings with hourly spot prices, but we really don't do fast adjustments on per-room basis. In a poorly insulated paper house, it's the exact opposite; it would be ridiculous to use the lower cost hours to proactively heat up rooms where no one is present, but in a glasswool insulated house with inner brick walls it totally makes sense.

author: tszaboo
author_rank: Super Contributor
timestamp: February 26, 2024, 07:31:29 pm
content: Quote from: Siwastaja on February 26, 2024, 06:21:16 pmOh no, I've been find out. I'm actually paid by big gas(?) and big district heating. Not someone who was actually interested in this technology, until I've been presented the shortcomings of the technology and calculated the costs of it for myself about a year and a half ago. And didn't see one particular post in 15 pages filled with wall of text. I clearly have an agenda here, good thing you have it all figured out.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 26, 2024, 07:48:57 pm
content: Quote from: Siwastaja on February 26, 2024, 06:21:16 pmYou got to love a good fight.Still waiting for the second set of quotes. I'm very curious as to what they are going to offer for air to water in terms of output power, and what the price will be for the complete job.What I know so far is that they mainly use Mitsubishi Electric for air to water with split units, so the pipes running to the outside unit hold the refrigerant and not the central heating water. This means they have to fill it with the gas themselves. In France there is a certification for heat pump installers called "Qualipac" and "certifRGE" so there is some reassurance that the ones we invited are not telling total porkies.Also keen to see which brand they will offer for the geothermal system.If they do a proper job and really perform calculations on the house based on what we told them about insulation and the measurements they did it should be in range with my own findings based on previous energy usage.For the geothermal a big portion of the expenses are the drilling of the holes. Unfortunately not a lot of companies around here do that kind of work.We just have to wait and see what they come up with.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 26, 2024, 07:58:11 pm
content: Panasonic also makes some quite decent air-to-water heatpumps, both monoblocks and splits. They do more conservative ratings than most others on the market so you basically know that unit rated for x kW nameplate thermal also provides it even at -15degC or so, making them more cost-effective than they first appear compared to the Chinese ones. I'm happy with my Chinese thing though but Panasonic was on my list of options and not much more expensive if at all. I believe they are somewhat cheaper than Mitsubishi Electric but not sure.

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 26, 2024, 08:09:51 pm
content: QuoteIs there a difference in life expectancy and reliability between tri phase and single phase models?For what I have seen of the De Dietrich models there is no difference in price between them. Don't know about other brands.

author: coppice
author_rank: Super Contributor
timestamp: February 26, 2024, 08:27:01 pm
content: Quote from: Siwastaja on February 26, 2024, 07:58:11 pmMy experience has been that Panasonic units are OK when new, but don't offer the lifetime of a Mitsubishi or Daikin. Which Chinese unit do you have? Some are really sophisticated, and high performance, which some are still pretty crude. People like Gree have put serious effort into making world class heat pumps, but that doesn't say much about their lifetimes. They don't have the kind of long track record of Mitsubishi or Daikin.

author: coppice
author_rank: Super Contributor
timestamp: February 26, 2024, 08:29:18 pm
content: Quote from: pcprogrammer on February 26, 2024, 08:09:51 pmUnless you have a bargain basement heat pump, why would three or single phase power make any difference? They are all inverter driven these days. Is this single vs 3 phase issue related to old heat pumps? I can definitely see a three phase induction motor giving better results.

author: nctnico
author_rank: Super Contributor
timestamp: February 26, 2024, 08:52:48 pm
content: Quote from: pcprogrammer on February 26, 2024, 08:09:51 pmI think the difference expressed is between on/off compressor versus variable frequency inverter driven compressors. Nowadays you will want an inverter driven heatpump as these are quieter under light loads. Also make sure to buy a unit with a rotary compressor as these produce way less vibrations.The outdoor unit I have from Panasonic has both and it sits on a sloped roof with a wooden construction. I have to listen very carefully to hear it from directly under the roof. But I have to say that I mounted it on extra shock absorbers.

author: tszaboo
author_rank: Super Contributor
timestamp: February 26, 2024, 08:57:48 pm
content: Quote from: pcprogrammer on February 26, 2024, 07:48:57 pmReading through your situ., I think the air to water heatpump probably makes the most sense. Especially since you have most of your house prepared for it.

author: Someone
author_rank: Super Contributor
timestamp: February 26, 2024, 10:44:54 pm
content: Quote from: pcprogrammer on February 26, 2024, 08:09:51 pmI know someone with an older 3-phase unit that was destroyed during a phase drop, but modern inverter units probably dont have that vulnerability.

author: tom66
author_rank: Super Contributor
timestamp: February 26, 2024, 10:53:32 pm
content: Pretty much every heat pump now, even with a single phase input, will be using a three phase compressor because they will use an brushless or induction motor and inverter to drive that motor. That will probably be immune to losing a phase (will likely cause the unit to shut off though if it has any monitoring of the AC line.)

author: Zucca
author_rank: Unknown
timestamp: February 27, 2024, 05:40:35 am
content: Did not have time to read all the pages...Once you understand the physics behind the heat pump you can't go wrong.This is what I did in my home in USA:1) I replaced my 50gal gas water heater in my garage with an 65gal electric heat pump water heater .2) I installed 14KW solar panels using the unused gas chimney to bring the HV solar cables down in the garage. (YES there is a metal ground shield around them... everything is safe)3) I installed my Victron inverters (16KW peak) and MPPTs few meters away from the HPWH.In winter the Victron devices are heating up the air and the HPWH is happy.In summer the HPWH is cooling the air and the Victorn devices are happy.I am now in the process to install 4 Temp sensors from my Cerbo GX so I can log all the in-out temperatures and see how much the two systems are helping each other.WIN-WIN!

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 27, 2024, 07:21:39 am
content: Quote from: coppice on February 26, 2024, 08:29:18 pmThat was what I was thinking too. We have a single phase installation but could change over to 3 phase at extra expense if it would be beneficial. Looks like it won't be needed.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 27, 2024, 07:29:18 am
content: Quote from: pcprogrammer on February 26, 2024, 08:09:51 pmNo. I think it is now impossible to buy line frequency on/off models. All are inverter machines, so there is no difference in the compressor motor, inverter power stage or drive logic. In both cases, incoming mains is just rectified. Assuming wye connection, three-phase inverter machine needs to work with internally higher DC voltage than the single phase equivalent, and single phase requires more DC bus capacitance to deal with more ripple, but such details are meaningless to normal end user.

author: Siwastaja
author_rank: Super Contributor
timestamp: February 27, 2024, 07:38:00 am
content: Quote from: coppice on February 26, 2024, 08:27:01 pmAmitime which I think is the second largest heatpump producer (after Gree). These large Chinese companies know how to get the basics quite right, they are not super sophisticated designs but then again a heatpump doesn't need to be. Whenever there are technological innovations that actually improve COP or performance (like inverter drive or EVI), first premium brands use them, then a few years later all the cheap ones adapt them too and make a big deal about it in their marketing, and then a few years later again it's just standard stuff and everybody forgets to even mention such technical details.Funnily enough, as a designer myself, I can see a lot of potential for quite significant cost savings in my Amitime unit. A cabinet full of stuff like Windows CE computer, separate wifi-RS232 module, total of four RS485 buses, and massive control cards with 20 relays out of 2 are actually used is something I would not expect from the market's cheapest product. They clearly can afford it, but they could also easily shave off another $50-100 from their manufacturing costs.You can clearly see air-to-water heatpumps are still quite niche compared to the ubiquitous air-to-air units which are better optimized for mass market.

author: JohanH
author_rank: Frequent Contributor
timestamp: February 27, 2024, 08:35:22 am
content: Quote from: tom66 on February 26, 2024, 10:53:32 pmThe ground source heatpump that I have, Nibe F1255-6, does have a three phase connection, but only one phase is used for the BLDC motor, which has its own motor driver (three phase 20 - 120 Hz). The second phase is used for control circuitry and pumps and the third only for electrical resistive heaters. You could run this model from a single phase. The resistive heaters are wired to all phases in this installation, but because they are almost never used, there is almost never any load on the third phase. Current load in this weather (outdoor 0°C): compressor is running on 600 W on one phase (right now motor speed 44 Hz), pumps on second phase 40 W and the third phase 0 W. The larger models of Nibe use induction motors with regular inverters and they might be differently wired. I've heard about some issues with some older heatpumps breaking when losing a phase. That could theoretically be protected with an external phase protection relay.

author: m k
author_rank: Super Contributor
timestamp: February 27, 2024, 11:28:45 am
content: Quote from: Zarhi on February 23, 2024, 08:26:26 amDo you know defrosting periods between different humidity levels?Here air-to-air machine is now using 400W and easily maintaining +21C indoors when outdoors is +1C and humidity being >95%.Some visible frost has accumulated but operation of the machine is stable and unchanged.When humidity goes up the efficiency of radiation process goes down but it also becomes more powerful per square.If pump ignores that it may overuse the situation.But changing 0C water to 0C ice is equal to 80C temp difference of liquid, so having sort of ice on top of the surface is not a straight forward thing.

author: coppice
author_rank: Super Contributor
timestamp: February 27, 2024, 11:42:28 am
content: Quote from: Siwastaja on February 27, 2024, 07:38:00 amI don't know where Amitime are in the rankings, but I think they are quite small compared to Gree, Midea and Haier. The big guys have the volume to finance the R&D to both performance improve and cost reduce their designs. An overly complex design is is something of a red flag. Midea is a big brand name, but they also make heat pumps that carry other big names, like Toshiba and Carrier. Haier products carry various names, but I think they are names they own.Quote from: Siwastaja on February 27, 2024, 07:38:00 amI think that is compartmentalised. Until recently the main market for air-to-water heat pumps was big commercial systems, and I think those should be quite mature. Consumer heat pumps have been mainly air-to-air heat, and mostly cooling only. That market has been highly optimised. The growing market for reverse cycle and heat only models is gradually getting those optimised, too.

author: m k
author_rank: Super Contributor
timestamp: February 27, 2024, 05:06:24 pm
content: Quote from: m k on February 27, 2024, 11:28:45 amI left and upped the target temp 1C, came back few hours later and indoor temp was heading to 22.5C and machine used 1770W.Dropped the target down 1C, no real operational change and room temp kept rising.After an hour or so later indoor temp is near 23C and machine is using 1100W, outdoor temp being a bit above zero and humidity over 95%.After few minutes of defrosting indoor temp meter says 22.5C and next cycle start using 960W, bit later it's 1200W.Now indoor temp is 22C, pump is chilling and using 236W, outdoor temp is probably under zero and humidity around 90%.Few log things.We have 3 different m3 styles, thrown, piled and solid.Our last piled qubes were 80EUR, first more mixed and later more pine.Here dry piled m3 of birch is said to have 1700kWh and pine 80% of that.Once we chopped an oak and a maple, not big.Those were very difficult to burn, oak practically didn't burn by its own.Maple was burning but needed a hot base.I also had free wood once.We collected what harvester left behind, the area was some hundred meters aside and wet.Collected trunks were chopped with a guillotine style cutter with a claw for splitting, nice thing but can't do too thick trunks.Putting in a bent trunk can also be a bit bad for nearby flesh.For me chopped logs were too long so I had to still cut them afterwards, the pile was also there, in the woods, so some hauling was necessary.Just for the sake of it I estimated how much the big pile would have been cost if sold, it was over 100EUR/m3 a long ago, at least a double now.Most of the time was used for collecting trunks, it took many days even when tractor collected small piles to big pile, but good exercise anyway.I'd say that free can be pretty relative.