I have a two story house with an occupied basement. Two HVAC units - one for the 2nd floor, one for the main floor/basement. Home is in East Tennessee, 2900 sqft.
The problem is that during the winter, the main floor thermostat showed it was in the bottom 10% of the comparable homes in my area. The 2nd floor got an Ecobee a few months ago, but it is showing that it was stellar during the winter compared to other homes. Now that we are starting to see some summer temps, the reverse is happening - the 2nd floor shows it’s suffering and the Main floor is stellar.
There is a stairway connecting the 2nd and main floor, so (as you can guess) with heat rising and cool air sinking, the two units can benefit statistic-wise depending on the time of year. I have set the thermostats up so that they are both set the same so any heat/cooling transfer between the floors is minimized, and that helps - but only a little bit.
The question I have is: Each thermostat is treated as if it is it’s own house. Is there any way to combine the two thermostats so that it looks at the house as a whole instead of two separate houses but under one roof (as Ecobee does)?
Note: The 2nd floor unit was just serviced. We found the coolant level was very low so this undoubtedly lead to unusual behavior (icing up) and resulted in wasted energy use. Ecobee alerted me when it recognized the temp was trending up a few degrees above setpoint even though the unit was on. I recognized the icing behavior using beestat and the tech was very impressed with how it was able to easily show the data. (Good job!) I may (rather, I do) have a small leak somewhere and I’m monitoring this unit, but while the efficiency is expected to increase, the question of combining thermostats still remains.