Watts to KW hours and cost

The basic math looks good. Keep in mind that the compressor tends to cycle on and off and I believe the watt figure is a maximum number with fan and compressor cycling.

So your actual average power usage will be lower.

Wes

You've got it kiddo. There will be fluctuations, of course, and the actual cost should be a bit less because the compressor won't be running all the time. The fan motor uses very little electricity. The only time the compressor will be running is when it is actually cooling.

Jim Chandler

You got it. Don't forget to add the transmission charges, taxes, etc. Simply divide your monthly bill total by that months kWh to get the true price.

Wayne

Correct.

And just for extra info: The SEER number is the number of BTU's' of cooling you are getting for each watt hour of your electric bill. The higher the SEER, the more cooling you get per $$$ of electricity.

And really extra > Hi people,

"RoyJ" wrote: \/

I have wondered about that designation forever. Thanks for the derivation, Roy.

Jon

thanks for that tidbit of info. i've wondered what that means when someone refers to "ton" when talking about AC. (i always assumed it had something to do with how much the compressor compresses the freon.) i know someone who often talks about "ton" and sometimes wonder if HE knows what it means. i'm trying to visualize how big a block of ice would be if it weighed one ton.

b.w.

p.s. just did a google search, found one cubic foot of water "weighs about

62 pounds". 32.25 cubic feet in 2000 pounds of water. just found "ice weighs 57.2 pounds". 34.96 cubic feet of ice to a ton. i couldn't figure it out so i cheated and went to and did like a reverse entry in the "cube". "3.2698 feet"

About 1 cubic meter, iffin I did it right.

Yeah, that ton ditty was great! Hope the ton etymology is right--I did enough damage quoting all that Cliff Clavin stuff during my Cheers Years...

oops--missed your PS-- but they seem consistent.

Quick and dirty "Rule of Thumb" estimate.

The wattage of an electrical device is approximately the annual cost of operating it, if it is on full time. It will be almost exact if electricity is 11.5 cents per KWH. But it is close enough to give a quick answer to questions like, "What does it cost to leave the bathroom light on all night?" etc.

Jerry

Get yourself a "Kill-a-Watt" meter for about $30 or so, available from a number of sources. Very handy little gadget which among other things functions as a Watt-hour meter so for your 120V 15A (1800W) or less appliances you can measure what the real world power consumption is. This is particularly helpful for items like refrigerators and air conditioners where most of the load is intermittent and the nameplate rating only represents the peak load which doesn't tell you much about operating cost. It's interesting to do an audit with the Kill-a-Watt and see where you power is going.

Pete C.

A good purchase. I did an audit of my house, put it on the frige, the freezer, computer, TV, etc. The big surprise was a reading lamp next to the "favorite chair" that cost $12 a month. It got switched to flouresent quite quickly.

Hi Wes and others,

Thanks for that, I had not taken the cycling into consideration so that is a little bonus. I really don't think I need the Kill-a-Watt meter as I don't care all that much. I was just wondering how much the A/C unit would add to the bill so I can decide how long to run it at a time. I will probably only use it for about 4 hours a day.

After about 7:00pm or 8:00pm it gets quite cool here in the Northern AZ high desert and usually a nice gentle breeze starts up around

8:00pm.

Thanks again to all who responded, very much appreciated.

22.99 at Amazon.com. Just ordered one, I have a feeling there may be some power usage changes in my near future.

Wes

I highly recommend Kill-A-Watts, they are very valuable, even just at debunking vacuum salesmen. (2HP vacuum cleaners drawing 8 amps, etc)

i

I find it to be a very useful accessory to use with my little Honda EU2000 generator I use with my camper. Really helps to be able to see the actual load I'm putting on it.

Pete C.