Energy savings of a ' fridge

[me]

Does the above REALLY work as well as they say?

have any real world experience with it?

[ransley]

That "Toy" as you call the KAW meter has quite a few reviews online stating accuracy is very, very good. I suspect your instrument is off, or your frige on the bum, since my tests, done on several friges conform to my utility bill at $0.13 kwh. Even an old unit I have, came up after a 4 day test at around $11 a month. If yours is really 1$ a day at near 0.13-$0.16 kwh then something, or a few things are wrong, Like your defrost timer is locked on defrost sucking an easy extra

600watts all the time, or freon is low so it never shuts off. $5 a month is an accurate figure a new 19.5 cu ft top freezer uses. I had a unit stuck on defrost from a broken clock, it took an extra 5-600 watts, those months we wasted maybe 50$ a month.

[ransley]

Lets see, as the piss ignorant naysayers say, Tankless water heaters save no money, condensing heat units are bs, CFLs you cant live with, and refrigerators cost $30 dollars a month at $.014 or so kwh, I say Bull shit, my tenants pay US$ 20 - 25 a month for electric for a one bedroom apt, with a 19.5 cu ft new HD Maytag frige and computer and TV games, I pay about US$ 35 for a house with an OLD FRIGE, , thats all, folks, in Chgo, and at a fairly high kwh cost of about $0.14kwh. What a bunch of whineing, dumb ass, weeenies you are on how to save bucks, morons, more like it. Talk about idiots that cant see through the clouds. My Neighbor, same size house, paid 700 a month to heat, I paid about 120, but he is too much of a moron to figure it out also, just like a few of the folks here. Refrigerators on the mainland, cant cost $30 a month, unless 15 kids keep em open all day. Piss it away, its only to the utility company, Bushes favorite personal investment.

[nicksanspam]

I think so. This started when Dr. Chalko (whose day job seems to involve helicopter aerodynamics) noticed that chest freezers used less electricity than fridges, despite their larger inside-outside temperature differences.

Then again, it would be nice if his fridge were larger and upright (for easier access and less floorspace) and had a freezer compartment for ice and ice cream. With just a few door openings, an upright freezer might work well as an ultra-low-power fridge.

USDOE tests freezers at 0 F in a 90 F room to make up for no door openings. The Energy Guide label on Whirlpool's EH151 14.8 ft^3 $369 chest freezer says it uses 354 kWh/year that way, so it might use 354(70-36)/(90-0) = 134 at 36 F, ie 0.37 kWh per day, or an average of 15.3 watts.

The A419ABC-1C digital thermostat from Johnson Controls ($62 as part number L38716 from Jonestone Supply, with a remote thermistor) uses 1.8 VA max. It could run the freezer when the box temp rises to 36 F.

If this is like Frigidaire's FFC1524 48"x29.5"x35" high chest freezer, with cold coils inside the left 29.5"x35" side and hot coils under the skin of the 48"x35" back, we might add an internal foil-foamboard partition parallel to the left side to make a freezer compartment and add more foamboard over the top of the chest lid and around the 3 cold sides and let a new stat run a small fan to circulate air between the freezer and fridge compartments when the fridge temp rises to 36 F.

Nick

[Wayne Whitney]

Hmm, looking at the EPA energy star data, they use about the same amount of electricity as fridges of comparable size. Which is still impressive, given the larger difference in temperature difference.

Another data point is to compare upright, freezer only, manual defrost units with chest freezers (which are all manual defrost, at least the energy star ones). For 15-17 ft^3, the chest freezers use 350-360 kwh/year. While for 15-18 ft^3, the upright freezers use 409-430 kwh/year. But, I haven't checked the energy star testing procedure to see whether they are opening the doors or not.

There are also commercially available chest refrigerators (e.g. by Summit), but they are much more expensive than a chest freezer conversion. I also couldn't find the usage data on them.

Cheers, Wayne

[Tennessee.Tony]

I know I'm late here but what I find unbelievable is that ten years ago they ran the same ads. That means a new energy star fridge of today uses 1/4 the energy of a twenty year old fridge.

I did have one of those "watt wizards" on an old fridge long ago and you could actually hear the motor make less noise as it was reducing the energy to it. I think it worked by sensing the speed of the motor and slowly cut back the power until it sensed the motor slowing down. Todays motors are just barely strong enough to operate the compressor. If you try to use a watt wizard on a newer fridge the compressor motor will stall.

Tony

[Richard J Kinch]

You claim $11 per month, so that's 11/0.13 = 84 KWH over 30*24 hours, which would as an always-on average load rate to just over 100 watts. A big refrigerator does not average 100 watts. It's more like 300 watts when it runs, and typical duty cycles with an icemaker are mostly running.

And don't forget my little gem of wisdom that your indoor refrigeration cost is twice as bad as your refrigerator electric cost when you are air conditioning, because you're pumping that heat twice, not once. Once from the refrigerator into the kitchen for $1/day, and again from the kitchen to outdoors for $1.25/day. So the accuracy of your outlet meter is not really the point, because it doesn't measure the true marginal cost of the refrigeration per BTU. This is one of the huge holes in the Energy Star claims.

[Richard J Kinch]

Please. $20/month worth of electricity won't run a TV set, much less heat, lights, or appliances.

I don't think it is even possible to get a $20 bill from our utility. The fixed charges are more than that.

[ransley]

I just talked to 2 of my tenants, they said they pay about 20 a month, thats for tv, microwave, lights, video games, computer, FRIGE, TVs, phones etc, at Chicago ill rates of near 0.14 kwh , so go figure, your mythical 1$ a day is from a bad frige or inacurate monitoring, show me a poor review on the Kill-A- Watt meter and its innacuracies, your monitoring of your frige is suspect, Gee I run a house at 39$ a month. Yours must be near 100 with 50$ pissed away in the trash. wake up and do your own audit old fart.

[Edwin Pawlowski]

I don't see that as a huge hole. I want a comparison of the appliance uses, not how my life is or is not affected by secondary functions. In my case, I only run the AC about 30 days a year, but if I lived in the south it may be

180+ days. Some of my neighbors have no AC, others have central units. it is impossible to give total energy use for every household in the country.

That tag though, does give me some idea that A is better than B. Perfect? No, that is why it is called an energy GUIDE, not an energy absolute use sticker.

[Richard J Kinch]

So you run a house on 300 watts average.

Pardon my skepticism.

[Richard J Kinch]

Exactly: it gives you that idea. An untested, unproven idea that plausibly could be the inverse of the truth.

The function of the tag is to sell refrigerators and provide cover for the government. No doors, no contents, no ice. A schoolboy doing a science fair project would come up with a better test.

[dpb]

Heat loss is heat loss -- all the other factors are simply changing the amount of same by either the same amount where something can be controlled well (as in a fixed weight of same items) or not so nearly the same as in more difficult to control (or at least much more expensive to develop test environments) of the door-opening that you seem so hung up over.

Again, it doesn't make any difference. It will change the absolute values, yes, but have very little bearing on the relatives...

--

[Richard J Kinch]

That's naive. Performance depends on the design, which varies for cooling room air, versus wall conduction losses, making ice, defrosting, etc. Efficiency has more to do with those parameters than any basic heat pump efficiency. That model A is better than B for the few modes tested by the DOE, does not mean that A beats B for other modes.

Indeed, the opposite is quite to be expected, since the design will be optimized to the DOE fantasy test, which appears on a big yellow immunized sticker, rather than performance under real conditions, which most consumers never measure. You know, putting stuff inside, making ice, opening the door. The DOE test forces designs that idle cheaply, rather than ones that cheaply recover from intrusions, defrost, or chill or freeze contents.

Quite typically the ultra-efficient designs get the last bit of efficiency from complex mechanisms that are the first to fail and fall-back, leaving you worse off.

[ransley]

Thats the problem you dont believe anything, I dont have any tenants paying over 20 a month with new friges unless they run space heaters. Read test reviews on a Kill a Watt and get one. If your frige costs 30 a month it should be junked.

[dpb]

Not really...heat goes from inside the box to outside and is kept there at some level.

The same amount of heat has to be transferred to cool N grams of water to make ice.

Again it would change the absolute numbers; unlikely to change rankings much at all.

--

[Edwin Pawlowski]

Do you have evidence that it may be the inverse? Have you done any testing?

The test is not perfect, the circumstances are not the same as every household uses their fridge in a different manner, but overall, heat gain into a given volume insulated container has to be removed. If two boxes, one more insulated than the other sit side by side in a 70 degree room, the better insulated one will have less gain. So, measure it, put it on a yellow tag and you have some basis for comparison. Real use will vary if you open the door five times or fifty times a day, but the comparison of A to BE will still be reasonably close. Add five pounds of water to each and make ice. You still have to move the same number of calories to get the water from 50 to 0 or whatever.

If the yellow tag sates $50 per year, my use may be 20% more, but the model that says $150 per year is still going to be 17% to 22% more and that is all I need to know. "Look honey, this one is better insulated so we can save a whale for dinner." That's all I need to know no matter how detailed your proposed test is.

I bought a car that states 30 mpg on the sticker and I'm happy with the 25 that I get and expected. I knew that difference up front. I do, in fact, know that it is better than the cars with the 20 mpg sticker and not as good as the ones with the 35 mpg sticker.

[Tony Hwang]

Hmmm, No sense arguing with a person like that. He is never happy with anything. Typically person like that blame everything/everyone but himself. That Energuide sticker is a quick reference for comparing A to B no matter what. If you are so energy concious, look at your life style first.

[trader4]

I think both sides of this argument have merit. The bottom line is, we really don't know how adding ice makers, a reasonably full load of food and opening and closing doors will affect the overall energy usage of the units. I would agree it's likely there is some corelation between the current energy test and how they will perform under more realistic conditions. I'd be surprised if the most efficient one suddenly became the most inefficient, but we really don't know.

I agree with Richard on one thing. That is the way they test them is not even close to how they are actually used. Unless I'm missing something, that means the stickers on all the doors showing the estimated annual energy used is not even close to accurate, as it's underestimated. And I would have to agree that it sure looks suspiciously like a way to fool consumers into thinking the new unit on the showroom floor is going to use less energy than it really does, which helps sell them. The tests were arrived at jointly between the EPA and the manufacturers and by having a test that is skewed helps the manufacturers sell units and helps the EPA by making it look like the Energy Star program is producing better results that it actually is.

[ransley]

Has anybody here read how the Energy Star test is done or what it tries to achieve. Years ago I found it and if I remember it simulated a family of 4 with doors opening up to 90f interior temp and doors not opened over 91f. Simulate it right, and it gets close even without food as the air must cool. Ive bought quite few 19cu ft friges, last year about 10, my tenants electric bills dropped about 10$ a month, my Kill a watt confirms usage on my new and old stuff. Sure you will likely pay more than ratings but comparing new to old, to the Energy Star units is pretty dramatic, If you look at all energy star tests there are 20% better units then gov average. Overall 50-75% savings over old units is a reality. I found I can beat the Yellow Tag with carefull use, my frige when tested with a KAW meter is as good as Sun Frost, which at the time was the most efficent with 6" of foam insulation, At .125 kwh I was paying under 5$ a month. Whats so hard to believe, ACs go to 20? seer, cfls save 75%, Boilers are up to

93-98%, 30 years ago few cared. Just 10 years ago my heating co would not recommend a condensing boiler because they felt there were reliability issues, now they do. If the tests were so far off it would be headline news. Doing your own test is easy with a Kill a Watt or other similar unit