You could get two remote bulb t-stats with 20' capillaries and C (common) NC (normally closed) and NO (normally open) connections. These can easily be wired with 120v in series with your fan. Wire one through the NC connection to set your house temp and the other through the NO connection to measure outside temp. That way they both have to close the ciruit for the fan to run and you don't have to monitor anything.
|