Controlling AC Usage

[Kevin Boyd]

I have several homes with swimming pools with gas and electric bills over $1000/month during the summer. On a couple of the properties the bills are in the $1500-$1900 range.. The homes are  2200-3500 sq. Ft. I know guests run the AC 24/7. We generate enough revenue that we can handle this expense but it would sure be nice to reduce these expenses. Does anyone know of devices that would shut off the AC when doors or windows are open or when nobody is in the house?