This isn't DIY, I'm trying to find a pro that can do this but my questions so far to locals seem to point to this not being possible unless we replace the furnance. So I figured i would ping this forum for thoughts.
We just had a central ac unit replaced and are happy with the install / pricing / workmanship. Part of the install happened to be the need to adjust the fan speed setting for the new ac unit. (old an new units are different tonnages)
The existing furnance is a trane xl 90 100k btu, it has a 4 speed blower fan.
So now the blower fan is adjusted for the heating (slot 4 high speed) and adjusted for the ac (slot 3 med high speed). All works as exspected.
In our home we have the blower fan run 24/7 in order to maintain a more level temperature (2 story with basement). With the new settings on the blower fan the fan noise is much louder (as exspected since it is set higher).
Honeywell Chronotherm IV Plus is the tstat
With the above setup is it possible to have the fan step down to one of the other 2 lower speeds (like slot 1 or 2)when the fan is on but there is no call for heat or cooling? If not with the above setup would it be possible to swap out something cheaper then a furnance and get the intended result?