Which is better, having a constant temperature set throughout the day for central air vs turning it up and down? At night I turn it up but isn't it more cost effective to keep it at a constant temperature than turning it up, only to turn it back down after an hour or two when it gets too hot inside? Doesn't that work the air conditioning unit harder because it has to make up for the time it was set higher? Thanks J Lease Jackiebrantlease@hotmail.com