Power consumption of a super efficient freezer at 120V and 3A over a 24 hour period?
Answer:
You are assuming the freezer runs continuously for 24 hours, which it doesn't.
I have a very old (25 yrs) huge chest freezer in my garage, definitely not built to today's efficiency standards, and in the Summer it costs me about $10 per month to operate it.
At $0.085/KWH, that's an average of 118 KWH/30 = 3.93 KWH/day.
In the winter, in the unheated garage, it is probably less than 1/2 of that.
120V x 3A = 360W x 1kW/1000W x 24 hrs = 8.64 kWh
The correct term would be *energy* consumption. Power is the rate at which the energy is delivered and that is a constant 120 * 3 = 360 Watts = 360 Joules / second
24 hours * 60 minutes/hour * 60 seconds/minute = 86,400 seconds
The total energy consumed, then, is:
360 Joules / second * 86,400 seconds = 31.1 MegaJoules
It sounds like a lot, but 1 Joule isn't all that much energy. You can turn a swizel stick in an iced drink 20 times and barely generate 5 to 10 Joules.
kiloWattt-hours is another *energy* unit, like MegaJoules. The guys above put the energy consumption in terms of kWhr (which is also correct).
.
Hold on a second guys . Is it running constantly? . not likely! If it's super-efficient, then it would probably be well insulated and well ventilated -- perhaps with a secondary coil to draw the heat away from the box.
If you know the cycling rate of the compressor, then multiply the above kWh by that rate.
If it uses 120 volts and three amps it has a power consumption of 120x3 = 360 watts. If it runs for 24 hours at that rate it would consume 8.64 kilowatt hours. Most regular-efficiency ones run about half the time so there goes about 4 kWh. If it was super efficient and everyone kept from opening the doors it might run only a quarter of the day so there is 2 kWh. At about 12 cents per kWh super efficiency would save you about 25 cents a day. Don't count on recouping the extra cost of a premium one with those savings. A typical refrigerator lasts for about 15 years so at $90 savings per year you would be luck to get back about $1300 over the lifetime compared to a standard one. That is a long wait for payback.
The answers post by the user, for information only, FunQA.com does not guarantee the right.
More Questions and Answers: