I have searched this site for info on 2 stage thermostats but haven't found the answer I have been looking for so I thought I'd ask. How does a 2 stage thermostat work? How does it control the staging? Time? Outdoor ambient? Reason for asking is everyone says 2 stage stats are much better than having the 2 stage furnace board control staging (12-15 minutes in low stage?) but no reasoning to it. How are they superior?