Question relates to system with Bryant two-stage heat pump compressor (3-ton), the FE4ANF002 air handler, and Evolution thermostat. We also have an Aprilaire humidifier integrated into the system.
We always set the fan to low and leave it there (both summer and winter). The compressor usually runs on the low stage, and we barely hear the air coming through the ducts….all good.
But yesterday (which was a humid and mild 50 degree F weather day), with the heat pump running on the low stage, I noticed that the air handler fan was running at a high speed, pushing much more air than usual. I am aware that, when needed, the Evolution system will run the fan at a high speed even when the fan setting on the thermostat is set to low (e.g., a very hot day in the summer, or very cold in the winter), but why in the world was it running at a high speed when the heat pump was just barely needed (and running at the low stage)? Do I have an issue…..or is this normal? But why would it be normal????? If anyone can solve this mystery for me, I would be very appreciative!!!