What's cheaper, on always or off and on?
OK, question me and my wife are currently arguing about.
Lets say the average temperature outside will be 80 degrees in the day and 65 in the evenings/nights, for the next 7 days.
Is it cheaper to leave the central air ON all the time, set at say 75 degrees... or is it cheaper to turn it off when you don't really need it?
When it's cooler outside than in the house, should I open the windows and leave the AC on, until the AC realizes it and turns itself off? Or should I set it to turn itself off first.
Basically, I posed this to my wife: "for example, if we leave the ac OFF for 8 months, and then turn it on and let it "get up" to our desired temperature, we SAVED a lot of money"
She told that's false, because the AC has to work that much harder to get back up to where we want it (even after 8 months of being off). Apparently it would use all the same electricity it would have used in 8 months, all in the same 2 hours to get the house cooled off.
So, what's the deal... I think my central air is about 2.5 tons. We have the upstairs door'd off and the vents upstairs closed, to force all the air to the downstairs vents...
I'm sick of the AC running all the time when its basically within 3-4 degrees of outside anyway.
I need something mathematical to explain to my wife why it's more cost effective to kill the AC when you don't really need it.