Got a bathroom fan to handle moisture (finally!). Fan good. Dry air good. Running fan when moisture is gone, bad – sucks heat out of the house. Turns out those crafty Californians have a code which led to the development of an occupancy sensor that never turns anything on – it only turns things off after a set time of no motion. So waltz in, turn on fan, take shower, leave – fan turns off on its own 30 minutes later. Sweet. (Normal occupancy sensors would turn the fan on when you go in to brush your teeth, which would be downright silly). It’s an “IPP15” from Leviton. Pair it with an ultra-efficient Panasonic fan and bask in your eco-righteousness.