Energy savings of a ' fridge

[Don Klipstein]

However, essentially all of the net heat output from a fridge is from the electrical energy consumed by the fridge. The heat being removed the fridge is heat that went into it from the kitchen.

Hypothetically, put a fridge in a large black box. So now you have a black box with a power cord coming out of it. The heat energy coming out of this box will equal the electrical energy going through the power cord. The law of conservation of energy does not care about what is inside this black box.

So a fridge consumes 1 KWH to pump either 3 KWH or some other quantity of heat out - but the heat removed from the fridge is nearly entirely heat that went into it from the kitchen. The net heat output of the fridge during a time it has consumed 1 KWH of electricity is going to be pretty close to 3414 BTU, which a good air conditioner can pump from the kitchen to the outdoors with about 1/3 KWH of electricity.

- Don Klipstein ( [e-mail])

[ransley]

I will simplfy it, I will make it easy, I get EPA yellow tag ratings, I tested mine, it works. I pay less than $5 a month to run my 19.5 cu. ft frige. Kinch pays 30 a month to run whatever, he is a sucker. Let him be a sucker or a moron, whatever. its his money, his waste, not mine or yours.

[ransley]

Get a KaW meter and test a new one, instead of guessing, bs ng discusing bs to death. I mean who cares, it works. Ive bought over 10 last year, they work. They save as advertised .

[Richard J Kinch]

Here's an Energy Star example:

They claim 606 kWh per year (8760 hours). So that's 606/8760 =

69 watts average consumption. Nowhere does GE seem to specify what the running power is, but based on my experience I would expect it to be 300 or 500 watts. So the duty cycle is claimed to be 69/300 or about 23 percent, actually less because we haven't counted the high-wattage defrost periods. We have to also guess at 1000 BTU/hr for the refrigeration unit based on its wattage. So this appliance is pumping maybe 6000 BTUs per day. Now you tell me how much ice you can make in one of these things running flat out, and we'll see how much the duty cycle has to increase to compensate at about 300 BTUs per pound of ice. Just to make a pound of ice per hour will more than double that duty cycle.

[Richard J Kinch]

So you claim to make ice without a sensible heat gain (which burdens the A/C) and corresponding latent heat loss (which does not)?

In thermodynamics and refrigeration, the money is always in the phase changes. Conduction losses are small change. Which is why the DOE test is silly, because it deliberately excludes any phase changing.

[ransley]

You forgot to read , defrost cycles are included, , DID YOU TEST ONE of just moan again

[ransley]

Moan moan moan, But you did no comparison, instead you admit you pay a total junker 30 a month

[ransley]

Did you test your JUNKER against anything, no you did not

[ransley]

Your basis on costs is not my basis , your 30 a month junker is just that, a junk , waiting to be junked

[ransley]

Wrong its near 80- 90 , ninety watts, mr Kincho, the problem is you have ZERO present experiance , but you think you do, which is BS, you never tested anything new, you test only posibly defective junk your unit, you have no independant view, you have only a biased view. your opinion is truely worthless. and based HOW, on what equipment , and what new units did you test, YOU TESTED NO NEW UNITS, YOU ONLY TESTED YOUR OLD JUNK. Your opinion is therefore BULL SHIT

[Don Klipstein]

A pound of ice per hour? 24 pounds of ice per day? How many people use that much???

- Don Klipstein ( [e-mail])

[Edwin Pawlowski]

That is a lot of guessing. I thought all your figures were based on fact.

24 pounds of ice per day = 3 gallons of water converted to ice. That is a lot of ice per day for a typical household.

[nicksanspam]

I can freeze a pound of water with 144 Btu on my planet :-)

Nick

[Edwin Pawlowski]

We just bought a new refrigerator at work. I'm looking at the manual and it states that the ice maker can turn out 2.5 to 3 pounds of ice per day. That won't affect the duty cycle very much.

[Richard J Kinch]

More than that. Maybe another 50 to chill it first. Plus wattage for a fan to blow air on it. And the defroster to take care of evaporation from blowing that air on it. Plus a reevaporator fan. And maybe the air conditioning. I would estimate more like 300 effectively.

[Richard J Kinch]

You consumption is not the issue, it's the rate at which the unit produces when it's running flat out. The issue was what happens to the duty cycle when the thing is making ice. My claim is that making ice is a bigger BTU load than perfect "idling" (no doors, no contents, no icemaking).

I think part of the problem is that my side-by-side refrigerator is a recent "efficient" type and not that old, but it is a big 25 cu ft unit with a rather large icemaker in it. The freezer side is big but the icemaker and bin take up about 1/4 of it. At the time when I was last buying a refrigerator, it was clear that the big ones had the same heat pumps in them as the smaller ones, they just ran them on a higher duty cycle. Which makes sense.

[Dave Martindale]

Freezing water does release heat which needs to be transported outside. But how much ice do you make? How many BTUs per month is that, compared to the heat leakage through the refrigerator walls?

Our refrigerator has ice cube trays, not an automatic ice maker, so I'm aware of exactly how often it's freezing water. It ends up being less than one cube tray per month. I can't believe that's a significant fraction of the heat load for an entire month.

Dave

[Dave Martindale]

Yeah, and you'd have to keep removing ice from the bin to keep the icemaker running to get even that output. Otherwise it will fill the bin and stop.

Here, we're unlikely to use 3 pounds of ice per *month*, except for a few months in the summer.

Dave

[nicksanspam]

My kitchen fridge freezer compartment is 0.5 F at the moment. It contains about 30 pounds of frozen food. Unplugged and "idling," it could easily make a pound of ice with a 10 F temp increase (ice has half the specific heat of water.)

Nick

[terry]

Interesting info; thanks for publishing.

BTW the difference between the 2.5 and 1.0 kWh (1.5 kWh per day) would, at our rates have a cost difference about 15 cents per day, or roughly $4.50 per month.

However any 'wasted energy' (i.e. heat from the older less efficient appliance) offsets home heating, when required. The amount is equivalent to a 1.5 kilowatt heater running for one hour per day. Since we use electric heating most months of the year don't think the difference would be appreciable or noticeable here!