Make-up air run to furnace cold air return?
I got my rough HVAC inspection on my gut remodel. I passed other than the inspector insisting that I install a 6″ duct from outside through a barometric damper to the cold air return of the furnace. This seems strange to me. I know that code requires make up air for a kitchen range hood that exceeds 400 CFM (of which ours doesn’t), but I didn’t imagine it would be run through the furnace. Wouldn’t the furnace draw outdoor air freely whenever it ran, whether the range hood was on or not? The house should be fairly tight, but the 96% AFUE furnace and condensing tankless water heater are both closed combustion.
This is the same person who a month ago preformed my plumbing inspection. At that time he pointed to my stand alone ERV and asked if it was my heating system. I told him that it is an ERV and is designed to take air from the bathrooms and kitchen adjacent laundry area and deliver fresh air to the bedrooms. He said he has heard of ERVs but had never seen one in the wild. He also seemed skeptical that it would serve in leu of bathroom vents. He didn’t bring up the ERV in today’s HVAC inspection.
Does the inspector’s requirement make sense? Won’t the furnace’s outdoor connection mess with the ERV’s balance?
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