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So, I am for the first time buying a freezer yet I am confused about the energy consumption.

On the website, it has this sticker:

enter image description here

I cannot work out if it means:

"This appliance will consume 168kw per year"

or

"If used for a whole year, this appliance will consume 168kw per hour which would (168*24)*365 = 1471680kw."

P.S Apologies if this is not the right place to post this. I have no idea where to look for help.

Mark
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  • Example: A certain hair dryer is described as 1400 W ( = 1.4 kW). How much energy will it consume in a 30 second session of use? Energy = Power x time = 1.4 kW x 30 s = 42 kWs. But nobody uses kWs so 42 kWs (1 h/3600 s) = 0.0117 kWh. – Jim Stewart Nov 20 '18 at 15:27

2 Answers2

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It means that the appliance will consume 168 kWh of energy in one year. 1 kWh (kilowatt-hour) is a measure of energy and is equivalent to the energy used by a device drawing 1 kW of power for 1 hour, which is equal to 3.6 MJ.

Here in the US, electricity rates range from about $0.10 to $0.40 per kWh, so one could expect to pay somewhere between $20 and $70 to operate that freezer over the course of one year. You can get a similar estimate using your own rate.

mmathis
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There is a unit called KWH which is distinct from KW. You kinda rolled right past that in your question. The H is for hour.

KWH is KW, for an hour. It is kilowatts x hours. (It is not kilowatts / hour).

Let's say you have a heater kicking out ~3000BTU or 1000 joules/sec. That heater is drawing 1.0KW.

If you ran that heater for 1 hour, it would use 1.0 KWH.

If you ran it for 5 hours, that'd be 5.0 KWH.

So if you have a unit that draws 168 kwh/annum, kilowatt and hour are on the top of that fraction, and year is on the bottom.

Note that year and hour are both units of time, and can be made to cancel out. We can multiply anything by 1.00 and it will stay the same, so we can multiply it by any fraction where above and below the line is the same thing: 1/1, 44/44, 1k/1000, or 24hours/1day.

  • 168 kWh/year x 1 x 1 = 168 kWh/year x 1 year/365 day x 1 day/ 24 hour.
  • Units can cancel too. "year" is on top and bottom, gone. 168 kWh x 1/365 day x 1 day/24hr.
  • Do the same canceling with "day". Giving 168 kWh/365/24 hour.
  • Hour also cancels out, so we have 168kw/365/24.
  • Remove the kilo: 168000w/365/24.

That is the number of watts the appliance burns on average. I don't have my calculator, you can do the math.

Or straight to your question: 168kwh/yr x 1yr/12month = 168kwh / 12mo = 14 kwh/mo.

Harper - Reinstate Monica
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