Here’s the system in a nutshell:
-3 story house, with upper floor partially open to main floor below.
-excellent winter solar heat gain
-wood heat on main floor.
-Broan 10 kw electric furnace with ecm fan motor (sort of… It’s the 13x)
-heating climate only, no cooling required.
The idea is that we know the stratification will occur, as the peak of the roof is quite high up. What I want to achieve is this:
A sensor up high will monitor air temperature at this level. A cold – air return duct is located at this height also. When the main floor thermostat calls for heat, the temperature of the air up high is used to determine weather heat is supplied by furnace, or if the fan only comes on, recirculating heat from up high throughout the house.
The high sensor is in place, wired to an empty box in the wall. From this box, a standard red 5-strand thermostat wire runs to the furnace (not currently connected).
The main floor thermostat (Zen thermostat)
Is connected to furnace with same type of red 5-wire, and also has a red 2-strand wire coming from the furnace in place but not connected.
Electrician says he thinks I will need a second "cooling thermostat" between the sensor and the furnace to make this work.
Is this the best way, or should I be looking into a PLC or HVAC-Controller? I just want to keep it as simple/inexpensive as I can given the system requirements. The logic seems straightforward, but how to best implement it?