Using swimming pool heater as air source heat pump - Page 1
Forum section: electronics / general

author: woodchips
author_rank: Frequent Contributor
timestamp: July 09, 2022, 07:34:15 pm
content: Swimming pools not that common in the uk, so never come across the air source heat pumps. Auction had a Hydro-Pro+ listed and bought it, not home yet to play with.Says it is about 11kW, COP of 6 with air temperature 25C. Can't imagine going to get that but says it will work down to -10C.Spring and autumn air temperature if 5C to 10C so wonder how well it will work, a COP of 2-3 is normal, so even that is a saving.Anyone else tried a similar heat pump? What amazes me is that air pumps are installed just a few inches away form a wall, so a fan is needed for airflow. Why not have a through draft so no fan needed?With current power prices might be an essential come winter!

author: Siwastaja
author_rank: Super Contributor
timestamp: July 10, 2022, 05:53:13 am
content: I have looked at it for fun.There is a risk -10degC is a bogus rating. Many of the cheap models I looked at lack the reversing valve and are not able to do defrost cycle. This would limit the low ambient temperature to around +5 .. +7 degC. But some models can reverse and defrost. It's still likely optimized to work above 0degC, and it can't do high temperatures. Heat distribution within your house is the big question.This being said, some are VERY cheap, and would be a bargain for house heating in conditions where most of the annual heating cost is around +5 ... +10 degC. You could fall back into other heating sources below that.The 11kW rating is likely optimistic, too.Large fan is always needed in air source units. If you extract 10kW by cooling the outdoor air by say 5degC (e.g. from +5 to 0), the amount of air that needs to go through is just massive. Hence large evaporator coil and a huge fan.I have EnergySave (ES) AWC9-R32-M, aka. Amitime HeatStar Monoblock installed, and it works without lower temperature limit. In my case, COP plummets to near 1 at around -20degC but that depends on the distribution temperature. If you have small radiators that need to run hot and don't want to spend upgrading them, you are out of luck. A very cheap swimming pool machine could still shave off some heating cost during easiest conditions.

author: srb1954
author_rank: Super Contributor
timestamp: July 10, 2022, 07:54:16 am
content: Quote from: woodchips on July 09, 2022, 07:34:15 pmThat quoted COP might be reasonable if it is discharging heat directly to the water, particularly if the temperature differential is quite low.A similar situation exists for large building chiller systems. I know that water cooled chillers can easily achieve a COP of 5 whereas air cooled chillers typically only achieve a COP of 3.

author: Siwastaja
author_rank: Super Contributor
timestamp: July 10, 2022, 08:30:56 am
content: Realistic COP for a well designed machine at Tout = Tamb would be around 10, around 4 for Tout = Tamb+25degC, maybe 2 for Tout = Tamb+50degC, and finally down to 1 at around Tout = Tamb+70degC.But the pool heater is not designed to discharge at much over 30degC. It is possible the thing just breaks down if you try to push it. (A well designed would give high discharge pressure error).

author: woodchips
author_rank: Frequent Contributor
timestamp: July 13, 2022, 01:24:21 pm
content: Further thoughts, why not dunk the condenser in a bucket of water so it extracts the heat from water rather than air, much more concentrated.Air is 870J cu m C, water is 3180J cu m C. Seems to be something wrong here, water only 5 times the energy density of air?But, that is to be sorted. Got roofs and water butts, a rain storm even in the middle of winter is at several degrees C, and a good down pour can fill a water butt. The butts are black so absorb sunlight. So why not use this free energy to heat your house?Like the ground source heat pumps, a good downpour will provide lots of heat to use, why run the collecting pipes 2m underground, just 0.5m is enough? This is the UK, wet and chilly, not freezing.Unit should come tomorrow, have to have a look at it.

author: Siwastaja
author_rank: Super Contributor
timestamp: July 13, 2022, 02:04:04 pm
content: Quote from: woodchips on July 13, 2022, 01:24:21 pmIf you have a large body of water, this is an excellent idea. It is doable if you have a lake next to you.Of course, you would not buy an air source thing and dunk the outdoor coil (it's called evaporator when in heating mode) in the water, instead you would use an unit which uses a proper heat exchanger as evaporator - these are sold under the name "ground source heat pump". Usually they circulate water-ethanol mix in a looooong pipework in soil, but if you have large body of water available, you can use that.QuoteYou sure can collect all the rain water from your roof, but then what? What if it does not rain for a day? Even in UK, that could happen. Besides, rain water will be obviously very close in temperature to outside air (or even colder - a bad thing), so there is nothing to gain compared to just using outside air.The whole idea of using ground source (such as running pipe in soil, or using a lake) is that during winter, it will be much warmer than air. For example, -30degC outdoor air temperature does not lend itself into air source heatpumping at all, but ground can remain at +5degC, a huge difference.But in UK, you don't have those harsh winters where -30degC is commonplace - you have quite warm and moist climate, just perfect for air source heatpumping. Air source gets a performance boost from high humidity (>80% RH or so) because the evaporator will condense the humidity of the air, increasing evaporator temperature. For example, I have noticed that if Tamb = +10degC and it's dry outside, Tpipe will get down to like +2..+3degC. Given same Tamb=+10 but with humid air, Tpipe is much higher, +6..+7 degC. Higher evaporator temperature then translates into better COP - not by much, but like 0.2 units.Just try the air source unit as is, they work perfectly in UK, no need to reinvent anything. Although the cheap "swimming pool" model might have some specific issues.Spend all effort to minimize the condenser (hot side) temperature, this means the distribution within house. If you just buy air-to-air unit (room air conditioner), then you are done - set the indoor unit fan high enough and you have decent COP. But if you pump air-to-water, and have old, small radiators which need very hot water, that will limit COP. Solutions then are, get bigger radiators, install fan coil units, install under floor heating pipes, or most ghetto, add some PC fans into the radiators to turn them into fan coil units.In fact, with the "pool" heater, concentrating on the distribution temperature is even more important. Unlike house heating models than can heat up to +50degC, these gadgets are not designed to produce hot water, because pools would be like +25 maybe +30 degC tops. If you need +50degC for your radiators, it is likely the pump shuts down due to high pressure protection, or worse, just breaks down. Even if it works, COP will be crap.

author: coppice
author_rank: Super Contributor
timestamp: July 13, 2022, 02:10:32 pm
content: Quote from: Siwastaja on July 13, 2022, 02:04:04 pmIf you go to some of the stately homes in the UK, which are now open to the public as tourist spots, you can often find this setup. These places tend to have a lake or river not far from the main house. Several of them have a small building by the lake or river, built in the late Victorian period, where a heat pump was used to heat the house from the energy in the water. Some of these are 150 years old, so the original installations presumably used steam engines.

author: coppice
author_rank: Super Contributor
timestamp: July 13, 2022, 02:16:23 pm
content: Quote from: Siwastaja on July 13, 2022, 02:04:04 pmIn the UK minimum temperature tends to follow maximum humidity. Air sourced heat pump exchangers have serious problems freezing over, unless they are sited in a very clear location with free air flow. Unfortunately, that requirement doesn't fit very well with the space around most UK homes.

author: Siwastaja
author_rank: Super Contributor
timestamp: July 13, 2022, 02:52:48 pm
content: Quote from: coppice on July 13, 2022, 02:16:23 pmI would really like to see better references about this. Defrost cycles generally work really well and are well tested over the whole planet. Seeing the almost unbelievably low numbers of installed air source heat pumps in the UK, I do get this feeling that them "freezing over" is more a myth than reality; a convenient myth not to install one, and keep burning the gas instead.Although I do understand it is possible. Climate in UK is quite a special beast.That being said, Japan also is an island, with colder areas up North, and they won't use much anything else except air source heatpumps for domestic heating.My heatpump has worked just fine during... British conditions, i.e. 100% humidity around 0degC.The known-difficult condition is freezing rain or very heavy precipitation of snow, combined with heavy wind which pushes the snow/ice into the unit, so that the unit has to deal with that extra external source of ice and snow. If they can't deal with the condensation they themselves produce, something is very wrong with the unit and its design.

author: coppice
author_rank: Super Contributor
timestamp: July 13, 2022, 02:59:18 pm
content: Quote from: Siwastaja on July 13, 2022, 02:52:48 pmThat's an oxymoron. The need for defrost, which uses a considerable amount of energy (latent heat of fusion is high) and stops the home heating until it is complete, is a horrible but necessary bodge.

author: Siwastaja
author_rank: Super Contributor
timestamp: July 13, 2022, 03:04:50 pm
content: Quote from: coppice on July 13, 2022, 02:59:18 pmYet, this is the reality we live in. Like having to stop in traffic lights is a horrible but necessary bodge - do you still go outside?I find it extremely funny how British posters on this forum have madecoming up with excuses not to install heatpumpsalmost an art.In the meantime, heatpumps are installed in large numbers in countries in which they perform much more poorly, and require much more defrost cycles - such as Norway or Finland.We get SCOP of 2 to 3 here, with a lot of defrosting. You would get 3 to 4.Why would you be interested in anything else but the actual, real COP (including the loss due to defrosting), and the fact whether it works or not, is beyond me.Also, did you ever stop to think about the enthalpy of going from gas to solid and back to gas? Apparently not.

author: coppice
author_rank: Super Contributor
timestamp: July 13, 2022, 03:19:00 pm
content: Quote from: Siwastaja on July 13, 2022, 03:04:50 pmBefore the energy market went crazy this year we paid about 4 times as much for a kWh of electricity as a kWh of gas. So, anything less than a COP of 4 represented a price increase. The sane way to use a heat pump is to heat air to 20C, and pass it around the house. However, in the UK few home make that easy, and a market for such conversions doesn't really exist. So, most heat pump installations heat water to 50C or 60C, and feed it to radiators in each room. In this sort of setup the COP is not 4. Just 2 or 3 is a good result. and that means your energy bill will be higher than using gas. Heat pump installations are far more expensive than boilers, and the pumps last half as long as a boiler when you raise the temperature to 50C. They last a lot better with a smaller temperature differential, so they are a lot more affordable when used to heat air to 20C.The stupid installations are why UK posters are resistant to heat pumps. The costs of universal heat pumps would take the UK back to the days before cheap natural gas was extracted from the North Sea, when I spend a childhood cold and miserable for half the year because only the affluent could afford to warm more than a single huddling point in their homes. We don't want to return to that, and the systems on offer in the UK won't bite the bullet and accept that we need to duct 20C air around the house if heat pumps are to offer a practical level of economy.

author: Marco
author_rank: Super Contributor
timestamp: July 13, 2022, 03:45:04 pm
content: You can use fan coil units, multisplits, add fans to existing radiators. Many ways to Rome for existing houses with hydronic loops. The problem is that installers deliver shoddy jobs.For new homes floor heating works equally well as ducts for heating, some people don't like forced air. There's no alternative for cooling, but you could have floor heating + FCUs.That said, I think small scale district heating with ground source heat pumps makes a lot more sense. Have one big industrial heatpump with a bunch of boreholes for a 100 or so homes, deliver 5/45/65 degree water to homes (through heat exchangers). For ground source heatpumps even 65 degree still gets decent COP, so if people want to use shitty radiators, they can use that. If they have something better they can use 45 and save some money. In the summer you get airconditioning and the ground is thermally recharged.

author: Siwastaja
author_rank: Super Contributor
timestamp: July 13, 2022, 04:16:24 pm
content: Quote from: coppice on July 13, 2022, 02:59:18 pmI need to come back to this because therein lies a fundamental misunderstanding.You seem to think among these lines: if the outdoor unit which produces 5kW, defrosts for 6 minutes every 60 minutes, while consuming 5kW, then the net gain is +5kW*54min - 5kW*6min = 240kWmin, much less than 300kWmin, right?Yet, real-world experience shows that well designed and built heatpumps offer nearly the same performance during dry room testing, or on field testing with defrost cycles. Only with worst offenders does the COP actually plummet. How is that possible?The answer is in understanding the enthalpy. Defrost isn't a problem after all, it's part of energy harvesting itself!Let's calculate it, per kg of water in high humidity of condensing conditions:From vapor to liquid: Gain, +2265 kJFrom liquid to solid: Gain, +334kJDefrost cycle:From solid to liquid: Lose, -334kJWater goes down to drain.Net GAIN: 2265 kJ/kg. Yes, defrosting now seems a solution, not a problem.In reality of course, harvesting energy by freezing water vapor into solid then melt it back into liquid requires moving energy back and forth, which is always lossy. Therefore, best performance is seen in heavily condensing but non-freezing conditions, where we gain 2265kJ without the further steps. If you compare to this best-case COP, the difference is of course bigger.Now let's add some realism:From vapor to liquid to solid: Gain 2265+334kJ = 2599kJ, but with COP=3, so need 866kJ of compressor workDefrost cycle:From solid to liquid: Lose 334kJ. But we need some work here, too. With air-to-water pump, average COP for this work is ~10, so need 33kJ of compressor work.Why is COP so high at this point? Because say you have 40degC water running in your house distribution system, and getting the outdoor coil to just something like 20-30degC is enough to melt the ice quickly. Theoretical COP is infinite because this is the passive thermal flow direction; compressor consumes very little current.But then, some of the water remains on the outdoor coil fins, and it's a really good idea to defrost completely enough to have dry evaporator, so actual machines do that. If 5% of water remains on the fins, this means:From liquid to vapor: Lose 5%*2265kJ = 113kJ. This is maybe with COP=5, so 23kJ of compressor work.COP is worse now, because we already need something like 60degC to evaporate the film of water quickly. This needs to be heatpumped from the say 40degC indoor water.The real elephant in the room is the duration after the water has been shed off. Every second, outdoor coil temperature is increasing, doing less and less useful work, while COP is going down. Most of the energy loss of the defrost cycle happens here: convection, or even worse, wind (fan is obviously stopped). Even well designed machines will here lose most of what was gained from the water enthalpy calculation, at very least - or even more.The "open space" mentioned earlier will make things worse, by allowing wind to cool down the outdoor coil during defrosting!But, the key finding is, even if we lost what we gained, we are notnecessarilynet negative - or if we are, at least not severely so. It is also crucially important to heatpump design toA) detect the necessity of defrosting cycle at correct time, not too early, not too late,B) do the defrost cycle as quickly as possible; air-to-water units have the advantage of having the large reservoir source of energy.C) terminate the defrost cycle as early as possible, but of course not too earlyMost units on the market do just fine, they could do even better with some crazy modern day software development, but instead they use simple, ages old algorithms which are hand-tuned with extensive testing during product development.TLDR; physically defrosting is not a problem and does not incur any energy loss. Practically, with good heatpumps, it is only a minor loss.

author: Someone
author_rank: Super Contributor
timestamp: July 13, 2022, 11:41:08 pm
content: Quote from: coppice on July 13, 2022, 03:19:00 pmSo your market was broken/distorted beyond sense, should have been installing tri-generation and ground-storing excess heat in that case. CCGT generators should keep electricity well below 3x the energy cost of gas, even open cycle is profiting at 4x. At which point modern heat pumps (annualized COP 4+) are the answer.

author: coppice
author_rank: Super Contributor
timestamp: July 14, 2022, 02:05:11 am
content: Quote from: Someone on July 13, 2022, 11:41:08 pmBut ONLY if you use a sane heat pump system, that isn't heating everything to greater than 50C. That's the broken and insane part of the current UK market. Ground sourced heat is a non-starter for most people in the UK.

author: Someone
author_rank: Super Contributor
timestamp: July 14, 2022, 02:36:10 am
content: Quote from: coppice on July 14, 2022, 02:05:11 amSo don't install a stupid over engineered nonsense system on the justification of sunk costs? The rest of the world (with worse climate than the UK) does just fine plumbing air-air systems into houses, its not hard.You say ground source doesn't work, except its being installed across the UK so other people think it does work. Despite that (which was a suggestion of more efficient uses for excess heat from tri-generation) just install air-air and get your cheap heating.You had a market which favoured inefficient country-specific solutions, good for you, globalisation is killing off those anomalies. The answer is not "give me back my broken market" but, get over it and invest in what works now and into the future.

author: Siwastaja
author_rank: Super Contributor
timestamp: July 14, 2022, 06:05:58 am
content: I wholeheartedly agree with retrofitting air-to-air units. You just need to get the installation culture going.I once looked at the economy of doing this, and in Japan where these units are common (90% of households has at least one), the cost of getting one installed is around 500 EUR (300 EUR for the unit, 200 EUR for installation). This is the lower limit where it can be if you do not have trade union like regulation of legalized installers to keep install costs artificially up.This is how it looks when you go to Asia, basically any country, this photo is from India:https://miro.medium.com/max/1400/1*Bw_P4L2mfbztAc36D6qOZA.jpegPeople are poor and can't buy expensive overengineered solutions. This limits their choices to something which have actually short payback time.

author: Marco
author_rank: Super Contributor
timestamp: July 14, 2022, 11:12:41 pm
content: Quote from: coppice on July 14, 2022, 02:05:11 amI think the economics can work for district heating with enough uptake. Assuming there is enough room below the sidewalk it's not much different from laying fibre. The trench has to be deeper, but they can shoot the pipes to the homes with horizontal "drilling", same as fibre. Buy back any existing heatpumps and sell them to rural houses at a deep discount.Air source heat pump industry would scream bloody murder though, I could see ISDS lawsuits.

author: coppice
author_rank: Super Contributor
timestamp: July 16, 2022, 06:06:25 pm
content: Quote from: Someone on July 14, 2022, 02:36:10 amI didn't say ground source doesn't work. I didn't say anything even close to that. I said its a non-starter for most people in the UK. Space is the issue. If people have suitable conditions on their property its the way people in the UK go, Even people who have no idea what a ground sourced system really looks like tell me its the way to go.Its a small part of the market, though. There is a lot of talk about running community level ground sourced systems under things like small local parks, warming the surrounding houses. I'm not sure there is much actual installation, though. Communal systems are fraught with problems as they age, need replacement, and not everyone wants to contribute.

author: Marco
author_rank: Super Contributor
timestamp: July 16, 2022, 07:05:48 pm
content: Just offer it as an utility, don't make people set up their own 2 bit communal company. The problem with communal solutions is sticker shock for sudden maintenance and replacement, large scale utilities are used to think statistically and can hide it all behind a steady monthly subscription.

author: Someone
author_rank: Super Contributor
timestamp: July 16, 2022, 11:42:55 pm
content: Quote from: coppice on July 16, 2022, 06:06:25 pmAgain, you walk the argument off to your preferred corner based on localsuperstitionconventionbad designs. Ground source does not need a field of shallow buried pipes (as the UK seems want to do) but works better in most cases with bore holes. Bore holes are a mature business and can end up cheaper than all the landscaping to cut and cover a shallow array, usually similar in price..... butthe "UK"you only looks at stupid ways of doing things and generalise that the concept won't work.So now you're going to have to come up with evidence that the majority of the UK cannot drill boreholes for thermal storage because of their geology, which doesn't sound right as commercial installers are promoting (and installing) ground source systems in general across the UK without * or warnings that its limited in application.

author: coppice
author_rank: Super Contributor
timestamp: July 17, 2022, 12:10:20 am
content: Quote from: Someone on July 16, 2022, 11:42:55 pmWhy do insist on being such a arsehole. This is nothing to do with superstition. We aren't free to do as we please. Building is heavily regulated in most countries, and we have to look as the options we have.At least in the UK you can't get permission to sink a borehole close to your neighbour's land. I'm not sure what the regulated spacing is, but its several metres. Several metres from the neighbour one side, and several metres from the neighbour the other side is an overlap zone for most houses in the UK. If several neighbours cooperate, this kind of issue can be worked around. However, unless they all want to install heat pumps at the same time this is probably not going to work out well.For new builds there's no issue of space at all. You can source heat from under the house itself. I think that's what they are starting to do in the UK. Its still likely to have long term issues, as maintenance of something under a house is a PITA. Anyone with a old septic tank under their house can attest to that.

author: Someone
author_rank: Super Contributor
timestamp: July 17, 2022, 01:24:07 am
content: Quote from: coppice on July 17, 2022, 12:10:20 amYou are the one making broad statements without any explanation, backup, or justification. Keep posting nothing statements and keep getting pushback about how you're just adding FUD rather than actual content/experience/numbers.We've gone from "Ground sourced heat is a non-starter for most people in the UK" and the only explanation you have so far is that theremightbe some planning restrictions possibly requiring some meters of clearance to the nearest boundary, which is easily done on most residential blocks. Even terrace houses (pretty much worst case for boundary spacing) are 5m typical width.Given there are a large number of businesses advertising ground source heating (retrofitting) in the UK and they explain how its possible to do on small blocks with limited access, it can't be a huge problem that preventingmostpeople taking it up. As a random example:https://www.nichollsboreholes.co.uk/faqs/QuoteQuoteSo the people who do this work have completely the opposite opinion to you, they say the majority of people in the UK can have a borehole ground source/thermal store. Who would the public believe? Random internet poster with no explanations or the people who actually do this for a job?

author: Siwastaja
author_rank: Super Contributor
timestamp: July 17, 2022, 09:08:10 am
content: Quote from: coppice on July 16, 2022, 06:06:25 pmAgain, you don'tneedground source heatpumping in the UK climate. Performance is only marginally better than well designed air source heatpumping, and latter scales much better.Ground source heatpumping is a prettycoolhot thing in Finland or Canada. Usually done here as a single 150-meter (or so) deep hole, doesn't need much space. But in a city with high population density, you can't heat every building like this, the replenishment of the ground heat will become a problem (might not, if active replenishment is used, which is totally trivial just not being traditionally done here. In practice this would imply summer-time ground source cooling, with excellent COP even without any compressor work.)

author: Marco
author_rank: Super Contributor
timestamp: July 17, 2022, 10:58:26 am
content: In dense urban environments all the sound from heatpumps adds up, it will get worse in a decade or so when bad cleaning and wear add up.Plus ground source heatpumps can directly provide high grade heat during winter and provide drop in replacement. Without the need for boilers or low temperature heating. People should get low temperature heating, but adoption will be better if they have the option not too.

author: Siwastaja
author_rank: Super Contributor
timestamp: July 17, 2022, 12:02:06 pm
content: Quote from: Marco on July 17, 2022, 10:58:26 amEuropean excuses of not getting heatpumps are total world-class comedy! Couldn't have expected THAT! I truly enjoy these cope threads.Though about trying to calculate it out for you, but why bother. Visit somewhere with gazillion of heatpumps installed, for example Japan. Makes absolutely no difference if you have any amount of car traffic.

author: Marco
author_rank: Super Contributor
timestamp: July 17, 2022, 12:25:58 pm
content: Quote from: Siwastaja on July 17, 2022, 12:02:06 pmMost people have no car traffic at night for the most part. Do you have a free standing property and did you have the ability to put your heatpump on the side of your house away from your bedroom window? Because people in row homes generally do not. Recently a new housing development here was banned from using air source heatpumps because the combined noise of a street full of them couldn't stay below 40 dB on neighbouring properties, the city said only a single one had to stay below ... the judge disagreed. No excuses, cold hard reality.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8297235/QuoteThe name of the lead author does not sound European to me.If we want near total adoption in dense urban environments, district ground source solutions make most sense. All the excuses add up and slow down the transition, noise, people expecting near instant heat without changing anything to their radiators, a whole family all wanting to have 15 minute rain showers etc. You can find them middling, but they're still important.

author: Siwastaja
author_rank: Super Contributor
timestamp: July 17, 2022, 12:33:17 pm
content: Yes, I do have a heatpump, a relatively large 9kW nominal model, right next to our bedroom. No problem. At full power, 90Hz, it can be heard during night because I live in countyside so it's dead quiet. Doesn't bother anyone. All neighbors have air source heatpumps too.Reality is what you make it. Yes, by all means accept cold hard reality. With your mindset, itliterallywill mean cold. And bloody - again literally. Enjoy.

author: Marco
author_rank: Super Contributor
timestamp: July 17, 2022, 12:39:19 pm
content: Quote from: Siwastaja on July 17, 2022, 12:33:17 pmThat does not answer my question. We have a free standing wall next to the bedroom and I am getting an air source heat pump and have no worries about it, but that's a blind wall, not the wall with the windows. A double brick wall is good noise insulation, the noise simply having to go around the corner helps a lot.My mindset can not overrule the judge regardless of what it is.

author: Siwastaja
author_rank: Super Contributor
timestamp: July 17, 2022, 02:41:49 pm
content: "Your" as plural included that judge. It is barely within the realm of reality that this judge was directly or indirectly financed by a certain country which does sell a lot of gas to Europe and also is known to manipulate public opinion. Heatpumps are a huge threat to fossil producers.I have a ventilation hole (kitchen exhaust) right above the heatpump which lets more noise through than any half decent window. Kitchen is right next to bedroom and we sleep with the door between kitchen and bedroom open. You can hear the compressor during cold winter nights when it's running at full power (compressor at 90Hz) through the wall and through the said ventilation hole, but... by "being able to hear" - just barely. If there is a car passing by - not the house, but even 100 meters away - that alone makes more noise, and more annoying kind of noise.Noise problems are usually due to bad wall mounting.Water flowing in radiators and ventilation also makes noise. Can't make our surroundings completely noise-free.

author: Someone
author_rank: Super Contributor
timestamp: July 17, 2022, 09:49:37 pm
content: Quote from: Siwastaja on July 17, 2022, 02:41:49 pmand as in the other thread where this came up, try getting the noise specifications for a gas powered heater! Oh look they're louder (but usually with lower duty cycle).

author: coppice
author_rank: Super Contributor
timestamp: July 22, 2022, 05:11:35 pm
content: Quote from: Siwastaja on July 17, 2022, 12:02:06 pmI've spent much of my adult life living where most people have heat pumps. Mostly for cooling, rather than heating. The noise from poorly maintained ones can be a huge problem at night.

author: Siwastaja
author_rank: Super Contributor
timestamp: July 22, 2022, 06:15:25 pm
content: You just need a control mechanism to deal with people neglecting correct installation and maintenance. Same for broken or removed car mufflers.BTW, each Finn, me included, has as of today's news been made to pay 1600EUR on average to the German natural gas customers. We Finns are known not to get on streets and put up with a lot of bullshit, thus we are easy to take advantage of. We don't usually get mad.I know this is not Germany's fault, it's the fault of our own corrupted leaders who think financing other countries is the job of Finnish taxpayers. Regardless, I want to appeal to all our German friends, consider using this 1600EUR subsidy I have had to pay to install a heatpump and thus reduce your dependency on the gas we are paying you. Paying your bills, I think I have the right to at least make this humble request. Also do note we are not that rich. Once we run out of money, you have to pay for your own gas after all. Thank you in advance for taking it into consideration.But I'm afraid the effect is opposite; cheap gas paid by someone else just makes people hesitate and not install heatpumps.

author: woodchips
author_rank: Frequent Contributor
timestamp: July 31, 2022, 03:52:50 pm
content: Glad this thread still alive, been so hot recently that done nothing at all about the swimming pool heater. Finally got it off the trailer ready to play with, now need some water pipe connections.Umm, Finland contributing 1600EUR to Germany, hasn't made the UK news. Did hear that Europe has been told to reduce gas consumption by 15%, but not cash handouts.Interesting times?

author: Siwastaja
author_rank: Super Contributor
timestamp: July 31, 2022, 06:35:48 pm
content: Quote from: woodchips on July 31, 2022, 03:52:50 pmAs always, it's not a direct handout of money, but a deliberate act that has been in motion for a fewyearsso that the final blow can be sold to us by saying "oh, somebody else fucked this up (and let's not tear open the old wounds) and now we can't do anything but to accept our fate", and so no one has to even resign.And obviously it only makes news in Finland, and pretty limited discussion here too thanks to the self-censorship.Seehttps://en.wikipedia.org/wiki/UniperSo basically what happened, somebody with good free lunches got an idea that Finnish taxpayers should buy majority share of a struggling German fossil fuel company in freaking year 2017, during active war in Ukraine and all that. Every imaginable expert said don't do it, and Uniper itself appealed to the Finns by buying front page advertisements basically saying "we are a crap company with near zero value, don't do hostile overtake on us". Yet that still happened. Fast forward a few years, and 8 more billion were pushed into this zero-value endeavor obviously because again somebody gets a free lunch. Finally, we were told that hey, everybody was right and this company has no value, so let's sell it to Germans again for peanuts to get rid of it, because if it went bankrupt, it would be Very Bad for Germans, and we don't want that.And the root cause to company being in trouble - their business strategy is to sell Putin's gas to German customers with massively long (I think they were like 10 years) fixed contracts, regardless of what the cost of buying that gas is. What could go wrong!So in essence, no money is being sent now. It has beenalreadysent during the last 5 years. We havealreadyenabled Germans to have Putin's cheap gas for years. Sad part is, almost no one knows about this. So no one is saying "thank you".This is the core issue in fossil fuels: they are not only bloody, but they are fundamentally expensive, being a limited resource requiring massive investments to extract. They can be only made artificially cheap, and indeedoneof the many ways to do that is to suck the money from Finnish taxpayers endless pocket because Finns are known to tolerate pretty much anything. 90% of us are too nice and even vote as being told to, and in the big picture it doesn't help that I'm not nice (at least to the criminals).But now it's over, we taxpayers here won't have basically any more money left. I think we will see some 5-10 billion still extracted for <some super important thing happening somewhere in Europe> but that will be literally the last before the collapse of our society, hopefully not a violent one.Sorry for going so much OT, I'm following your project with interest because those swimming pool air-to-water heatpumps sometimes go for really cheap, like 500EUR for a new unit, and they are powered by standard plug so no electrician is needed, just plumbing. These will obviously not work when it's -15degC outside and you need +50degC water in your distribution, but if they worked at Tout = +7 to provide 35-degC water, at decent COP say at least 3, that would already be a huge saving as you would need to burn the fossils only small part of the winter.But as always with air-to-water heatpumps, lowest possible distribution temperature isthe#1 key to success. This is true even with state-of-the art expensive units, but of course even more important with the swimming pool heater, because I think no one heats up a swimming pool beyond +35degC or so, so the units might fail by refrigerant overpressure, hopefully giving a soft error message instead of getting actually damaged, but being cheap, I suspect protections will be lacking.And low distribution temperature might be surprisingly easy to achieve: for example, install 1-2 fan coil units in parallel with the old radiators, something like that.

author: Marco
author_rank: Super Contributor
timestamp: July 31, 2022, 10:57:59 pm
content: Fan coil units are ridiculously hard to get in my country at decent cost. Still gotta check with distributors, but for direct consumer sales there is pretty much nothing affordable (to the point I can just buy a minisplit for the cost of a single FCU). They seem to be big in Italy, also affordable.I want to see if it's possible to get a monoblock which can do cooling and supplementary heating through a couple FCUs, blocking the normal radiators from the water loop during cooling to prevent condensation, but switch automatically to re-supplying a boiler for domestic hot water when required. I'm afraid it will be gibberish to installers here.

author: NiHaoMike
author_rank: Super Contributor
timestamp: August 01, 2022, 12:08:07 am
content: Quote from: Marco on July 31, 2022, 10:57:59 pmLook at using car radiators and then finding PSC or BLDC fans to match.

author: Dankoozy
author_rank: Contributor
timestamp: September 02, 2022, 03:08:40 pm
content: Quote from: coppice on July 13, 2022, 02:10:32 pmReally? Are there any pics of such an ancient heatpumps?I was dragged around loads of National Trust houses by my ma back in the day and never saw such a thing. I did see plenty of ice houses from the time before mechanical refrigeration though

author: coppice
author_rank: Super Contributor
timestamp: September 03, 2022, 05:52:18 pm
content: Quote from: Dankoozy on September 02, 2022, 03:08:40 pmI saw them 50 years ago, visiting places with my parents. I can't remember which houses I saw them at. However, I haven't seen many stately homes, and I've seen more than one Victorian heat pump at one, in its own little building down by the lake or river, so I assume there must have been quite a few around. Trying to Google things like "Victorian stately home heat pump" just gets me stuff about people trying to install new heat pumps in old houses.

author: Marco
author_rank: Super Contributor
timestamp: September 03, 2022, 06:08:59 pm
content: A little search for heat pump history tells me Swiss seem to think they originated commercial heat pumps for heating around WW1. Victorian England seems a little early by comparison.

author: coppice
author_rank: Super Contributor
timestamp: September 03, 2022, 07:10:21 pm
content: Quote from: Marco on September 03, 2022, 06:08:59 pmAre you talking about electrically powered ones? WW! sounds about right for that. Early electric fridges also date from around that time, too. In the Victorian era heat pumps for refrigerated warehouses, and the ones I saw heating stately homes, used a steam engine.

author: Marco
author_rank: Super Contributor
timestamp: September 03, 2022, 07:32:05 pm
content: Even if you used the heat from the steam engine for conventional heating too (most of the energy goes to heat after all, maybe 20% to motion), just using the heat pump to boost the temperature of the already hot water ... it just doesn't seem worth the investment.Ohh, you get maybe twice as much useful power out of the coal ... for the cost of a steam engine and a state of the art heat pump which probably uses ammonia, so which can easily kill you.

author: coppice
author_rank: Super Contributor
timestamp: September 03, 2022, 07:40:29 pm
content: Quote from: Marco on September 03, 2022, 07:32:05 pmI guess they didn't necessarily have to work especially well. Wealthy people loved to show off how very up to date they were. If you had a large heat pump, in its own building, with a viewing gallery, all your friends could be impressed when they visited. Its rather like buying an EV to look very up to date, when all the electricity in your area is produced from brown coal.

author: Siwastaja
author_rank: Super Contributor
timestamp: September 04, 2022, 06:07:40 am
content: Using the river for a micro hydro power installation, and using that power to run a heat pump sourcing heat from the very same river would be an interesting way to heat your house, if you live by a river, of course. This would make total sense for very small rivers/creeks which cannot provide more than a few kW of electrical power, which alone isn't enough to heat a house, but multiplied by the heatpump COP would suffice.