[Greenbuilding] Looking for a whole-house fan thermostat

[Chris Hutchinson]

Hi all,

I've got one of those super-efficient Tamarack whole house fans, and since it has to run longer than the old Velcro-down-the-kids-or-they'll-get-sucked-into-the-blades models, I would like to get a thermostat with an outside (maybe wireless?) sensor that would enable the fan to turn on and off mostly by itself. I'm in Fort Collins, Colorado so I've got warm days and cool nights, and like to bring in cool evening air so that the house is cool in the morning.

I've looked pretty hard and even the pricey t-stats I see that have an outdoor sensor don't seem to have the ability to use the input as an alternative set point. Here's what I would like my mythical thermostat to do - namely, turn on when the outside temp is lower than either the set point or the inside temp and turn off when the set point is reached OR when the inside is the same as the outside. I could then simply set the thermostat for, say 60 degrees and here's what would happen (starting in the morning and cycling through to the following morning):

Out        In            Fan
55           60           off
58           62           on
62           62           off
80           64           off
85           66           off
75           68           off
68           70           on
60           65           on
55           63           on

Does this make sense? I'm beginning to think that I'll have to get an X10 controller, receiver, and 2 temp sensors to do this - yet it would seem like something that someone should have made for people who want to use outside evening air to cool the house instead of an air conditioner! If we can't find one I've got dibs on the patent - this could even be a plug into the wall unit that could do window fans or stand fans.

Please let me know your thoughts.