On Jun 27, 10:21*am, Chief Two Eagles wrote:
On Sat, 26 Jun 2010 13:31:37 -0400, Tony wrote:
I'm trying to figure the cost of running the central AC in my house.

Run it one month and then look at your electric bill.

I see two approaches. For the macro view, as per the above, just
comparing electric bills for summer with months in Spring or Fall with
no AC or electric heat use would give a decent approximation. My
utility bills show usage by month over the last year. I can easily
see the effects of running the AC. Of course, if you had some other
seasonal load, like pool pumps, etc, that could complicate things.

For the micro view, as someone else suggested, record the electric
meter for a time period on a day with no usage and then do the same
with the AC on.