Posted 2/7/2019 17:38 (#7304345 - in reply to #7303360) Subject: RE: Fresh air coming down bathroom exhaust fans.
You either have inadequate cold air return to the furnace or no exterior ductwork for combustion air for the furnace. Suggest you have a HVAC contractor do an inspection. Both reduce efficiency of your system.
Fresh air coming down bathroom exhaust fans.
