Wrapping up my basement finishing project. Total square footage of the entire basement exceeds by a good bit the total cubic square feet of combustion air required per total BTUs of my HWH and HVAC.
These units sit it what was once a hall and are open to a 12x12 storage room. That storage room has a door. On the other end is drywall. I'm going to be putting large high and low grills in that drywall and also one lower in that door. I figure I don't need high/low in the door as well.
So effectively, with these grills, the entire basement is one big open space for combustion air for the units.
However, on the drywall side - there just happens to be a supply vent very near where I'd want to put the high grill. The supply is in one stud-cell - and the most logical and nicest looking spot for that high grill is in the next stud cell - mere inches from the supply vent.
I don't know how much combustion air those units suck in. But I'd hate to negate the coinditioned air coming out that supply vent by having it get sucked right back into the combustion air grill. I know combustion air openings aren't like return vents, so not like a vacuum.
So - does it matter how close the grills are to a supply vent? My only other option is about 5 feet further away.