# air conditioner kwh

I'm not sure if I am reading my digital electric meter correctly. It appears to say that my house uses 2.1kwh during the day when no one is home, 3.4 during the night and 16kwh during the day when the air conditioner is running.

The first two numbers are believable. Could my air conditioner attach to the house be really using 14kwh during the moment it is running? I tested the meter by turning on 2 lights (40w cfl and a 60w Incandescent). It should be +.1 but it appeared to be +.27 which is 3x what it should be.

My power bill is 550kwh a month which seems average but the numbers i notice seem weird

14kWh = 14,000 watt hours

That means 14,000 watts for one hour, 7000 watts for two hours, or 1000 watts for 14 hours. Given that a central air conditioner might draw 5000 watts, you could easily see 14 kWh in a day.

Make sure you don't confuse watts & kilowatts which are instantaneous measurements of electricity rate, with kilowatt-hours, which is a measurement of total consumption over a period of time. It does not make sense to ask "could my air conditioner be using 14kwh during the moment it is running".

But to answer the question with some ballpark numbers: we've been having a heat wave on the east coast (maybe you too?), and I measured one of our window units using 6 kWh during a very hot one day period, for one room. The average US household uses 30 kWh per day, although of course that will vary widely from house to house and from one region to another.

• The meter refreshes every few seconds. One number is the amount of consumption and I can figure out the kwh used by the house by subtracting it with a reading X days ago. The other number has a decimal and it went from 2.2 to 15.YZ in less then a minute and fluxuate by .2 except when the AC went on. I meant "the moment" as in if it ran like this for the hour would it be 14kwh. I'm going to do readings and mark the time throughout the day and maybe I can understand what the number actually is. I'll find it odd if its estimated kwh per day rather then kwh if it continued for the next hour
– user14079
Jul 20, 2013 at 20:03
• @acidzombie: The meter's display should show what units it measures, if it is a modern design you can probably download a manual for it. Watts are a measurement of power which is rate of energy flow in Joules of energy per second. 1000 Watts (1 kiloWatt) for 1 hour (3600) seconds is 1 kWh or 3600 kiloJoules of energy. Jul 21, 2013 at 9:18
• @RedGrittyBrick: hmm, I could see the two light bulbs being 50watts and the meter telling me kilo joules per second
– user14079
Jul 21, 2013 at 9:37
• I'm still not clear about what readings you're getting from the meter and what units they're in. 14kW instantaneous usage would be a little higher than I would expect from a single-family house, but isn't necessarily impossible if several large appliances were running at once (central AC, water heater, electric range, etc). 14 kwH in a day is totally reasonable—in fact it's under the US average.
– Hank
Jul 22, 2013 at 0:19