I don’t know what to think of this one. Why would there be air return ducts installed like shown in photo for the two units? I wrote them up as a Safety Hazard because they were within 10 feet from the combustion. The furnaces were High Efficiency units. Do you think they were installed to balance the pressure of the air return?
Biggest safety issue with a close return is that it could draw gas from the hood but since it is a cat 4 it is not as much an issue.(no hood).
The space looks big enough to not be a closet so it may be allowed from a safety standpoint.Otherwise it would need to draw from outside the closet.
Guessing flex makes the unit less noisy however is there a good seal to the compartment and is there a working filter in place?
Not seeing the connection or other side makes it hard to Judge.
They are probably to take the fumes out of the room that the latex cans in the background may give off in the future.:roll:
Where they returns or make up air?