How many kwh per day should an a/c take?

mousebandit · #1 07/03/07, 12:44 AM

In addition to the lovely water problems, we've been getting slammed with $250/mo electric bills. This is about 3x what the owners were paying last summer, so the electric company has suggested I check how much power is consumed while using the heat pump (on a/c) as compared to when it is turned off. Then we are supposed to do the same thing with the water pump breaker turned off. They said one of these is probably malfunctioning and needs repair.

I checked the usage without the heat pump a/c turned on, and we were using about 42 kwh per day at that rate.

Then, I just put the a/c on for an hour and a half, and checked again, and the power consumption went up to a rate of 146 kwh per day!!

How do I determine if that is outrageous power consumption (indicating that the heat pump is needing repair) or if that's just what it costs to run an a/c?

I've tried googling and checking lots of websites, but I can't seem to get a number of kwh I should expect a heat pump to use per day or month with normal usage.

THANKS!

Tracey Mouse

Windy in Kansas · #2 07/03/07, 06:26 AM

For starters look at the electrical label on the AC unit. It should give the electrical draw, probably in amps. Amps X volts = watts. 1,000 watts for one hour is a kilowatt in order to figure your consumption.

pixelphotograph · #3 07/03/07, 07:07 AM

the reason you cant find a number online is there are to many variables.
it has to do with the size of your heat pump and the age as well.
there are also seer ratings which tell you how efficient it is supposed to be.
so what windy in kansas said look on your unit and it should give you what you need.

agmantoo · #4 07/03/07, 10:21 AM

Use this calculator for a rough idea.
http://www.unit-conversion.info/energy.html

Do you by chance have a 22,000 BTU to 24,000 BTU A/C ? If so, then your numbers are correct.

texican · #5 07/03/07, 01:19 PM

If you're a/c is using roughly 100kw a day, at my rates of 7c/kw, that'd be 7$/day...210$/month... I'd say that's a little steep for air conditioning. Of course, the heat pump shouldn't run all the time, and if you turned it off for a while and then turned it back on, it could've been running the entire time, throwing your daily computations off as well.

In our neck of the woods, there's a power surcharge added to the bill... which can add as much as 40% to the overall bill.

morrowsmowers · #6 07/03/07, 02:34 PM

Your rates sound about right. We have 2-1/2 ton central A/C, electric dryer and electric hot water tank, 4 TV sets, 5 computers, etc., etc. etc. but we do have CFL's in almost all of the lamps. Our bill is on a budget of $262.00 per month. It was $340.00 before we installed the CFL's.

Ken in Glassboro, NJ

Windy in Kansas · #7 07/03/07, 09:26 PM

I'm glad that I've learned to live without air-conditioning.

My last electric bill was $20.43 for 32 days, yielding a consumption of 5.6 KWH per day. I could cut back some more but I kind of enjoy some convenience. lol.

A little more conservation and I'll be ready for solar or solar and wind and off grid.

Liese · #8 07/04/07, 04:42 AM

Tracey, Have you had a tech from the electric co come out and check the meter? When we moved here to the farm there was a 1 month period between closing (so the account going into our name) and actually residency. I got a bill higher than what my actual bills usually are. Turned out the meter was sending bogus info. They installed a new meter and we've been fine since but I do keep an eye on the KWH/day and know approx. what I should be seeing. Good luck.