I bought a house built in 2005, ~4100 sq. ft.
Reasonably insulated to code, as required in Chicago, IL.
I've got an upstairs thermostat and downstairs thermostat. Both are Nest thermostats specifically, and I can track the daily run times.
Once we hit sub 30 degree days, I've noticed that the downstairs furnace will run for 6 hours but the upstairs furnace will run for like 13 hours, to keep everything at 68 degrees.
First thing, I noticed is that the upstairs thermostat is in the master bedroom and usually behind a closed door and the rest of the upstairs with open doors was a few degrees warmer due to better air circulation.
I adjusted our upstairs thermostat to sit at 65 degrees vs. 68 degrees downstairs to try to compensate for that.
Even with the changes, I haven't seen the variation shrink too much. The upstairs furnace just runs way way longer.
Is that typical in a bigger house like this? I always thought "hot air rises" -- in our old townhouse the upstairs would be smoking hot, to the point we need to close a damper.
This house seems completely opposite.
Aside from a possible HUGE hole in a duct somewhere that feeds upstairs, is what I am seeing normal?
I think if I measure the duct heat upstairs vs. downstairs it should be close...?
Intuitively there is a LOT MORE DUCTWORK for that heat to make it's way upstairs from the basement. Does that typically dominate for heat loss vs. "hot air rising"?