I have two gas furnaces and two gas hot water heaters going into one vent, problem?
Yes I would say problem, 2 is the max that I’m aware of with the lower btu going on top…
See page 19:
But the connections look funky. I’d refer it out.
Beat me to it but only because I was busy booking…
Manifolds are fine if done properly.
This is in an outside utility room with no dividers, no vented openings, and the dryer vent terminates just beside one of the furnaces.
So there are two gas furnaces, two gas water heaters, and at least one dryer(possibly two) vented to this room. The only air can be drawn from the attic and around the exterior doors.