Good Monring All:
I have heard and understand that there are two speed fans, and variable speed house fans that are intended to work less during the warmer days but do any of these actually control the speed of the direct vent fan?
I inspected a home with a YORK gas furnace and while I was upstairs raising the thermostat, the agent and client witnessed some “strange noises” from the direct vent fan (its a newer furnace). While we standing there the little fan really slowed down in RPMs and there was very little CFMs coming out the supply ducts.
I thought the direct vent blower should be a continuous speed regardless what the house fan is doing.