i have a new high efficiency furnace and the installer has intake air coming from both outside the house as well as an intake inside the furnace room, is this acceptable practice? I also have a radon mitigation system in the house which functions well. I'd like to know if the indoor intake can draw potential radon air into the system and possibly recirculate that air throughout the house??
Generally you can pull combustion air either from the interior or exterior. I ALWAYS tell people to pull from the exterior. Exterior combustion air draw eliminates the useless wasted time that you are now going through. If the basement is open it isn't a big deal, there's usually plenty of air.