How many kwh does a refridgerator freezer from the 1990's use? - Page 1
Forum section: electronics / general

author: Beamin
author_rank: Super Contributor
timestamp: August 22, 2017, 04:01:38 am
content: The people I live with seem to think that a 7 watt LED being left on over night costs hundreds of dollars per year but they look over the early 1990's fridge freezer whos compressor never shuts off.I can't see anything about the model as I have no access to the back but I'm just trying to figure out how big these compressor motors are then a simple calculation:kwh per day is easy because it never shuts off.These motors are called sealed units but online it just has these calculators that are probably wildly inaccurate because they don't show you the math.I'm also trying to figure out how much taking a shower uses if you have an 80 gal tank and leave the hot water turned all the way up and use the cold to regulate the temp.For that:Heat capacity of water 1g/1'C= how much heatDelta T = 15'C to 80'C?Flow of faucet LPM times minutes on = 20 X showers per daySize of coils and efficiency: Amps X 240V X efficiency X time: I'm guessing the coils convert close to 100% of the electricity to heat as they just sit in the water and have no transformers or electronics.Not going to take into account loss through tank as the tank is cool to touch or pipes as it doesn't matter; hot runs at 100% flow rate.I hate making CO2 and run my electricity like a Nazi.

author: Ampera
author_rank: Super Contributor
timestamp: August 22, 2017, 10:02:56 am
content: My thinks is that they are just from a time when 100/120 watt bulbs were common, and leaving on on all night COULD eat into your electric bill.I mean if you want to figure it out, get an inline power meter, and plug the freezer in. I'm pretty sure you can figure out where to take it from there. If you don't know what I'm talking about, Big Clive often uses them to check current draws from the various bits of tat he looks at and often tears apart (Truly, a master of don't turn it on, take it apart).

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: August 22, 2017, 05:06:43 pm
content: A compressor should not be running all the time. Check if the coils are caked with decades of dust, or perhaps get someone to check the refrigerant level, if such a profession still exists for home units...

author: Zero999
author_rank: Super Contributor
timestamp: August 22, 2017, 05:47:57 pm
content: I agree, the compressor shouldn't be running continuously. Is it the right temperature or too cold and freezing up? If it's the correct temperature, then there could be a problem with the thermal insulation, door not closing properly or the refrigerant level being too low. If it's freezing up, check the thermostat is still working and the contacts haven't welded closed.

author: Mr. Scram
author_rank: Super Contributor
timestamp: August 22, 2017, 07:09:09 pm
content: Calculating the power consumption is a wild guess. You either need to get a power meter, or could maybe disconnect all other devices and groups and check the consumption on your meter after an hour or two. You could run such an experiment at night to reduce the practical impact.

author: rdl
author_rank: Super Contributor
timestamp: August 22, 2017, 10:16:36 pm
content: You can get a Kill a Watt or similar power meter for around $20 or so. They're useful, everybody should have one.

author: Mr. Scram
author_rank: Super Contributor
timestamp: August 22, 2017, 10:25:42 pm
content: Quote from: rdl on August 22, 2017, 10:16:36 pmI don't use mine often, but find it rather useful when I do. It's great to have as a quick sanity check.

author: Beamin
author_rank: Super Contributor
timestamp: August 23, 2017, 09:39:36 pm
content: Quote from: Hero999 on August 22, 2017, 05:47:57 pmThis unit is not worth fixing as you can tell by the motor running all the time. The Freon is the older r6 type and you can't put the hi/lo gauges on it or refill it. Cost benefit analysis of both operating costs or repair plus operating costs dictates buying a new one, but I don't know how long I will be in this area so I don't want to buy big appliances an have to leave them behind.Killawatt I couldn't think of the name.Unfortunately it can't be connected to the hot water tank. Shutting things off isn't going to work as this is a huge house and would impact the two other people living with me. Plus I like to learn the math behind things.I found in my last house that running the heat was logarithmic; above a certain temp the heat would stay on all the time. You cut the electricity in half by lowering a few degrees since the hot air heaters are running 100% or 0%.

author: floobydust
author_rank: Super Contributor
timestamp: August 23, 2017, 10:09:02 pm
content: Problem is modern refrigerators don't last (as) long, they are really cheaply made now.You think it's better for the environment and savings on electricity, but the opposite is true - they cost more because of repair bills and the disposal costs.Just vacuum the condenser coils and fan, they get plugged with dust after a few years.Or the door seals leaking, the defrost heater stuck on, or defective thermostat etc.

author: Mr. Scram
author_rank: Super Contributor
timestamp: August 23, 2017, 10:12:08 pm
content: Quote from: floobydust on August 23, 2017, 10:09:02 pmI guess this would be the time that actual calculations could shed some light on the matter. And yes, I know that calculating the actual costs of something in regards to pollution and hidden costs can be a highly controversial topic.

author: Beamin
author_rank: Super Contributor
timestamp: August 23, 2017, 10:41:40 pm
content: Quote from: floobydust on August 23, 2017, 10:09:02 pmIts low on r6 and free of dust or leaky door seals. If it was that simple I would have already done it. You can't buy R6. To convert the system to modern Freon it would require cutting into the system and venting out to the atmosphere. You can't vacuum out the r6 because you can't get the hi/lo gauges on to connect to the vacuum tank. To make the vacuum fit to it you would have released the r6 defeating the purpose. Also the physics of r6 is different then r123a so they are going to change states at different temps and pressures requiring different nozzles. Maybe modern ones don't last as long but so what if I get 6 years instead of 10? Electricity cost has made it pay for it self. I have yet to spend any money on calling a refrigerator repair man in my life or paid to put a fridge out on the corner so in that respect that cost is zero but in your country it may be different.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: August 24, 2017, 02:40:01 am
content: Quote from: floobydust on August 23, 2017, 10:09:02 pmThere's a 55 year old McClary fridge at my parent's summer place. It's been running whisper-quiet since I was a little kid (and it was already old even then).It has a tiny freezer compartment that doesn't self-defrost.

author: BradC
author_rank: Super Contributor
timestamp: August 24, 2017, 02:51:18 am
content: Quote from: Beamin on August 23, 2017, 10:41:40 pmI assume when you refer to the refrigerant as r6 it actually says that somewhere on the label? I can't find a refrigerant definition for r6.In any case, any decent fridgie would put a vampire into the process tube and evacuate the refrigerant that way, they'd then vacuum and re-charge one of two ways. They'd use a process tube adapter and then re-crimp/braze the process tube or they'd braze on a service fitting and do it that way. You're right in that it's probably not economical. Your refrigerant likely contains chlorine which works well with a mineral oil. Any replacement would require an oil flush and replacement with a synthetic oil, but the reality is if your fridge is low on refrigerant it has a leak. You'd need to find and fix that first. The other option is the compressor valves are weak and it's just not pumping effectively.If you get caught "venting out to atmosphere" these days, you'll wind up with your entire local greenpeace chapter at your doorstep bearing recyclable pitchforks and led torches. Most countries have pretty serious legislation for the release of refrigerants.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: August 24, 2017, 04:22:49 am
content: You will have to make measurements to get real numbers. There are too many ways for models to fail. For example what is the heat transfer coefficient between your water heater and its surroundings? Between those surroundings and the outdoors?It wouldn't be too hard to get a current measurement from the water heater although it would involve breaking the power line and then inserting a killawatt would be possible.Two points of reference -1. We unplugged a 1970s upright freezer and knocked $30 dollars/month off the electric bill. Shows that the payback time for a new more efficient unit is short - measured in single digit years, and possibly fractional years. That is in a low to moderate electrical cost area. I don't recall and haven't gone back to look at the kWh savings.2. People have been crying "They don't make them like they used to." for decades. In the mid 1980s people were claiming that old chest freezers lasted forever but the current ones die within 5 to 7 years. We bought one and it is still plugging along today. Not as efficient as a current model, but not bad, especially since most of the improved efficiency comes from improved insulation which can be emulated external to the current model. The moral here is that people remember the old device that is still working, and forget all of its brothers and sisters that died decades ago. So the old stuff will always be viewed as better and longer lasting. That tungsten bulb still burning after 100 years had hundreds of thousands, and perhaps millions, of peers that burned out 80-100 years ago.

author: hermit
author_rank: Frequent Contributor
timestamp: August 24, 2017, 04:41:25 am
content: On a unit that old look for 'cap tube separation'. The little tube that carries the freon back into the freezer is fixed to the suction line. Sometimes they come loose. It makes about a 10F degree difference. Sometimes they run inside the cabinet making them hard to find.

author: floobydust
author_rank: Super Contributor
timestamp: August 24, 2017, 05:24:49 pm
content: I looked at the numbers, comparing a 1999 vs 2017 top tier efficiency 22 cu. ft refrigerator (850 vs 425 kWhr/yr, rate $0.12kWh) and initial cost of $750.Savings about $51/year in electricity. Over a 14 year life you'd save $714 total.But the new energy efficient fridge doesn't last 14 years. Let's say it lasts 7 years. Gotta buy a new one for $750 which is $862 including inflation at the 7 yr mark.Including 2% inflation, in today's dollars the 14 year fridge projectyou lost $900 because the cheap piece of junk did not last.It's the purchasing cost amortized over 14 years for Fridge #1 and 7 years for Fridge #2.We could do exact math, including repairs etc. but my numbers show the electricity costs are small compared to the fridge replacement cost.

author: hermit
author_rank: Frequent Contributor
timestamp: August 24, 2017, 07:27:01 pm
content: Energy regulations have made it so that manufacturers have to squeeze hard to get every watt possible out of their models. That means you get appliances on the margin of what they can do so they do have to work harder than their older counterparts. That doesn't mean quality has declined though. Over the past 35 or so years the warranty rate of repairs has dropped from over 10% to around 3% today. The cost of repair makes it necessary to build them better. You should average at least 10 years on a modern appliance in the US.

author: ejeffrey
author_rank: Super Contributor
timestamp: August 24, 2017, 08:31:27 pm
content: Quote from: floobydust on August 24, 2017, 05:24:49 pmNo, your math with made up numbers showed that they were roughly comparable within the precision of your guesses. Except that your 7 year number is almost certainly wrong, and you didn't factor in that a 15 year old refrigerator probably is less energy efficient than when it was new. It might be able to be restored to original performance by servicing, but you did not add that to your cost.I really doubt that the average time to failure of refrigerators is dramatically lower now than it was 20 or 30 years ago. It might be a bit less, but I would doubt it is below 10 years, and I would expect more like 15. A cursory check of refrigerators sold per year (about 11 million) would support this, although it is hard to account for what fraction of sales are to replace broken fridges vs. new capacity or upgrades.Normally people complaining about this are basing it on a friend who bought a new fridge and it failed in the first year or so, while their 20 year old fridge is still running "like a champ". That is the bathtub curve in action. One thing that is different now is that appliances are (relatively) cheaper and service is more expensive. So a failure is more likely to result in replacing rather than repairing, especially if it is out of warranty. But if you are comparing costs of old vs. new, you have to include the expected repair costs, not just purchase costs and energy use.

author: Mr. Scram
author_rank: Super Contributor
timestamp: August 24, 2017, 11:12:33 pm
content: Quote from: floobydust on August 24, 2017, 05:24:49 pmThose numbers sound a bit like they are made to fit the conclusion, if I'm totally honest. If I look at numbers from fairly reliable sources, at the refrigerator pricing around here and the costs of electricity, the break even point is around 5 years or a bit more. Considering my current fridge has been running for 10 years without a hitch while taking a thorough beating (admittedly a huge dataset) and that I cannot recollect hearing of refrigerators failing, ever, I feel the 7 years estimation is very pessimistic.

author: b_force
author_rank: Super Contributor
timestamp: August 27, 2017, 02:05:20 pm
content: Quote from: hermit on August 24, 2017, 07:27:01 pmWell, that's even not completely true.It's all about insulation and basic physicsBefore we go into that, I would like to refer to these pages first;https://coolfridge.blogspot.com/In fact, the best way is to have a fridge that opens from the top side, simply because of how thermodynamics work.That way you can run a fridge on a bunch of batteries for a loooooooooooooong time.

author: floobydust
author_rank: Super Contributor
timestamp: August 27, 2017, 05:31:11 pm
content: My point again is reliability is far more a cost saver than energy efficiency, due to repair costs.Modern fridges have more parts and more complexity and higher price: ice-makers, electronic control boards, condenser fans, French doors etc.LG offerfor their compressor to get better efficiency, but they don't seem to last.Samsungnotice the electrolytic capacitors next to hot semi's.These babies are expensive to repair and getting 14+ years life is unrealistic, IMHO.Energy Star calculatorfor payoff buying a new fridgeEnjoy the $186 savings on the $500 repair bill lol

author: b_force
author_rank: Super Contributor
timestamp: August 27, 2017, 05:38:38 pm
content: The main point is that manufactures only go for the bare minimum to safe money.It's the same concept as the everlasting light bulb, which easily can be manufactured.The problem is that you won't sell anything after a while anymore.Most pump systems haven't really being changed that much the last few years.And ones again, going more efficient, simply means insulate the hell out of it.Basic physics.

author: Mr. Scram
author_rank: Super Contributor
timestamp: August 27, 2017, 06:16:08 pm
content: Quote from: floobydust on August 27, 2017, 05:31:11 pmMost people who buy fancy refrigerators with all the bells and whistles buy them because of just that. They want something that's new and nifty and care less about how long the thing will last. They will buy the next new and shiny thing in a few years anyway. In short, refrigerators that die quickly are servicing that specific segment of the market.If you're not interested in gadgets, but simply a refrigerator, you can buy a good quality normal refrigerator. They easily last 10, 15 or even 20 years. Looking at the numbers on the internet, they seem to be in agreement. The only sources coming close to your 7 years estimation are in the repair and sales themselves and can hardly be called objective.I've heard about worn out washing machines. I've heard about central heating needing replacement. I can't recall ever hearing anyone about a refrigerator failing or needing replacement for reasons other than cosmetic, noise related or power consumption.

author: floobydust
author_rank: Super Contributor
timestamp: August 27, 2017, 06:20:14 pm
content: Adding insulation certainly helps, just touch the outside of your fridge/freezer and feel the losses. Insulation is thin and cheap to save cost and wall thickness I think.But... also energy loss due to the door being open/closed the average 33 times/day.Is the insulation part of the electrical energy kwh "number" that we all look at? Or just a power meter reading?I could not find the actual Energy Star test parameters. They might ignore it, if the door is opened so much.

author: Mr. Scram
author_rank: Super Contributor
timestamp: August 27, 2017, 06:23:36 pm
content: Quote from: floobydust on August 27, 2017, 06:20:14 pmAdjusting your use can make quite a lot of difference indeed. Not putting hot food in it, defrosting things in your refrigerator rather than on the counter top, taking out multiple things at once instead of opening the door multiple times and putting them back before they've got time to heat up too much.People don't want to think about it, but considering the huge percentage of the electricity bill a refrigerator generally is, it can really pay. A good rating is worth less with more abuse.

author: b_force
author_rank: Super Contributor
timestamp: August 27, 2017, 06:31:01 pm
content: Quote from: floobydust on August 27, 2017, 06:20:14 pmLike I said before, the best solution is make the door on the top, not on the side!I don't follow your question.More insulation means that the fridge needs to be on less.So yes, that will translate in a lower energy bill.Don't care what the 'Energy star' tests are, just basic physics.But to be honest, my electric stove still uses most of the energy.Far more than the fridge.For that reason I try to use only one or two plates.Also, for just heating up left over, a microwave is much more efficient.(power vs time)

author: CatalinaWOW
author_rank: Super Contributor
timestamp: August 27, 2017, 06:33:32 pm
content: Quote from: Mr. Scram on August 27, 2017, 06:16:08 pmI've had about the same luck with washing machines, freezers and refrigerators. MTBF about 20 years. Standard deviation about 12. There are examples of all three categories failing early.In refrigerators it is often repairable (fix leak-replace coolant, replace capacitor and compressor that failed secondary, etc.) but is seldom economic.

author: amyk
author_rank: Super Contributor
timestamp: August 27, 2017, 06:37:10 pm
content: Quote from: BradC on August 24, 2017, 02:51:18 amThe only refrigerant that comes to mind as starting with a 6 and being obsolete is R-611,methyl formate, althoughapparently you can still buy and refill old fridges with it.

author: Mr. Scram
author_rank: Super Contributor
timestamp: August 27, 2017, 06:45:38 pm
content: Quote from: b_force on August 27, 2017, 06:31:01 pmElectric stoves are the worst. I'd take gas over electricity every day, even though I hear that induction plates are actually a decent experience.

author: b_force
author_rank: Super Contributor
timestamp: August 27, 2017, 06:53:37 pm
content: Quote from: Mr. Scram on August 27, 2017, 06:45:38 pmActually, gas is getting more expensive here than electricity.Induction is pretty nice.The problem with my stove is that it has a glass plate.Just search for the thermal resistance of glassElectric stoves are pretty fine, but ones again not much has been improved since the stone age, simply because they are super cheap to manufacture.With just a little bit of engineering thinking, it shouldn't be so difficult to make these thinks MUCH more efficient!!

author: David Hess
author_rank: Super Contributor
timestamp: August 27, 2017, 06:54:42 pm
content: Quote from: floobydust on August 24, 2017, 05:24:49 pmI made this upgrade a couple years ago in order to extend the run time of my backup generator and make a battery backup system more economical and those were about the numbers I estimated and later measured using a power meter. The newer refrigerator drew about half the energy but the payback time may exceed the expected operating life. See below.QuoteThe newer refrigerator also failed at about the 7 year mark because the evaporator fan motor quit. They used to use shaded pole motors for this which were utterly reliable and inexpensive but the new ones use a permanent magnet motor with electronic commutation and have an atrocious failure rate compared to the old ones. The new ones are also expensive.Also on the new refrigerator, the drain for the automatic defrosting tends to freeze over and the bail on the ice maker is not heavy enough to reliably return. These problems are more annoying than fatal but they indicate poor quality and reliability.

author: David Hess
author_rank: Super Contributor
timestamp: August 27, 2017, 07:07:06 pm
content: I have gotten used to using a dual coil element electric stove. My only complaints are that it will not work with a curved pan like a wok and in some cases, the power settings are too coarse.

author: floobydust
author_rank: Super Contributor
timestamp: August 27, 2017, 08:26:14 pm
content: Quote from: b_force on August 27, 2017, 06:31:01 pmIn North America, most appliances have compliance regulations regarding their energy efficiency.They get a huge sticker with their energy efficiency rating, kWh/year number.US calls it Energy Star, Canada calls itEnerguide. I am not sure what your country uses.When shopping for a fridge, you see one model has a higher number (lower energy), so you are inclined to purchase it.I wanted to know if the insulation is a factor for the test and the assigned number.I found theUS Dept. of Energy fridge energy test parameters. Appendix D2. It's an empty fridge with a complex weighted-average including where you live "weather factor"Probably pull a Volkswagen and cheat the tests lol, just don't run the defrost/anti-sweat heater etc.

author: b_force
author_rank: Super Contributor
timestamp: August 28, 2017, 12:13:36 am
content: Quote from: floobydust on August 27, 2017, 08:26:14 pmI really doubt it.Normally these tests are something like, turn on the fridge at a certain measured temperature en see how fast it cools down something.Or how much energy it uses for x-amount of time.How (much) the fridge is being insulated is not relevant for a label.Hopefully you also understand that you have to take these labels with three containers of salt.

author: floobydust
author_rank: Super Contributor
timestamp: August 28, 2017, 12:52:58 am
content: I understand the "tests" are a government exercise and rating number a bit off from reality. Most people haven't taken thermodynamics courses and don't understand refrigeration and heat transfer and where the energy goes.There's a push that newer is always better, "a new fridge uses less electricity" - true but it uses more money...It's unfortunate that if you work out the total cost- fridge's electricity use, manufacturing, environmental, repair costs, you'll find it's easier on the planet just to make the thing last.

author: Mr. Scram
author_rank: Super Contributor
timestamp: August 28, 2017, 01:00:40 am
content: Quote from: floobydust on August 28, 2017, 12:52:58 amI've seen you claim the last bit before, but I haven't seen it substantiated. When looking at average refrigerator lifespan I did find a somewhat credible source that calculated that the energy cost of replacing a refrigerator is actually fairly low, due to the fact of them using a substantial amount of energy, and that most of it can be recycled, limiting the energy required. Obviously, there is a point where it becomes senseless, but replacing 10 to 20 year old refrigerators does not seem all too unreasonable. Most, if not almost all, seem to last that long.You obviously feel strongly about this, but that also is not quite the same as it being so.

author: ejeffrey
author_rank: Super Contributor
timestamp: August 28, 2017, 03:33:12 am
content: I don't know about refrigerators, but I found a while back an analysis by Ford or GM (don't remember) on the lifecycle energy cost of a car, to answer a similar claim about fuel efficient cars. The entire energy cost of production of a (conventional non-hybrid ICE) car is about the same as the fuel used in about 2-3 years of average driving. So all those people saying that it is more energy efficient to drive their old beater into the ground rather than get a new higher MPG car are just wrong, unless your "old beater' is a 2000 honda civic that gets 38 mpg.There is more to environmental impact than energy use, but cars and major appliances are highly recyclable. And whether it is an economically good decision is another factor: a new appliance (or car) costs a lot more than just the energy cost.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: August 28, 2017, 04:13:17 pm
content: Quote from: ejeffrey on August 28, 2017, 03:33:12 amWhile I tend to generally agree with the sign of the conclusion on energy cost - I would be leery of an analysis by a major auto maker that concluded that: "Yes, you should buy a new car, every three years."I would look for holes like an assumption that 100% recycling was achieved, that all recycling processes used optimum energy efficient methods, that average driving was 25k miles/year, that the mileage of the car being replaced was 10 mpg, that transportation costs of employees working at the recycling plants were not incorporated and the like.So while it may indeed save energy to buy a new car, the real number might be 7-8 years, a number much longer than Detroit wants you to drive a car before buying new.

author: Beamin
author_rank: Super Contributor
timestamp: August 28, 2017, 06:50:18 pm
content: I refuse to watch any video where the people film with their camera phone in portrait mode. Why can't they just turn the phone on its side? Then they move the camera all around making you motion sick and you can't really see what's going on.

author: Zero999
author_rank: Super Contributor
timestamp: August 28, 2017, 08:14:17 pm
content: Quote from: Beamin on August 28, 2017, 06:50:18 pmYes, that annoys me too, especially the motion sickness, which I'm very susceptible to.

author: StillTrying
author_rank: Super Contributor
timestamp: August 28, 2017, 08:37:04 pm
content: You can work out how many Watts are in use by timing the flashes of the meter's LED, if it says something like 800 flashes/ kWh, then 1 flash per 45 sec. = 100W, you can do it without turningeverythingelse off.

author: Beamin
author_rank: Super Contributor
timestamp: September 04, 2017, 02:15:30 pm
content: Quote from: StillTrying on August 28, 2017, 08:37:04 pmwhich meter? the kilowatt?

author: hermit
author_rank: Frequent Contributor
timestamp: September 04, 2017, 04:18:12 pm
content: Just so that dead horse doesn't get up and trot away....One thing that is typically overlooked when calculating energy cost is the totality of the environment. We had a cooler than typical early September night and my furnace kicked on. How much energy was my refrigerator "wasting" last night? Other than natural gas might be currently cheaper (Forbes said this might not be the case by 2020) the fridge just puts out waste heat that is not really waste for probably a minimum of 4 months of the yearly total run time.

author: StillTrying
author_rank: Super Contributor
timestamp: September 04, 2017, 05:50:51 pm
content: Quote from: Beamin on September 04, 2017, 02:15:30 pmNo, the flashing LED on the leccy supplier's meter.

author: David Hess
author_rank: Super Contributor
timestamp: September 04, 2017, 06:38:10 pm
content: Quote from: Beamin on September 04, 2017, 02:15:30 pmHe is referring to the utility meter. If you have a Kill A Watt meter, then you can just connect it between the refrigerator and wall socket which is what I did to accumulate data for about a week on the old and new refrigerator.