I've been in my new place about a year and have been dinking with various things to reduce energy consumption. I've added a modest amount of new insulation (ceiling to R-50) and a radiant barrier upstairs, switched to CFL's and basically use common sense to turn stuff off when not using it.
My air handler seems to run about 15-20 minutes every hour for ventilation purposes. That chews up a fair amount of KWH a month. The Honeywell IAQ stat has settings to control CFM (don't know if that would work with my Trane XL 14i and 2TXCB048AC 3HCAA air handler) and a setting to have ventilation with the fan on or off. It also has a setting for ventilation limits of 30%, 50% and 100% Does ventilation work without the fan? I admittedly am confused, but then again my wife insinuated that when we got married.