Return air near furnace

I have been finding more return air vents close to the furnace and sometimes right above the filter area. I know this is a safety issue on older furnaces. Does it still apply to direct vent furnaces?


Not allowed in this state period???

Shouldn’t be a problem with sealed combustion direct vent system but still not the best of practices. Check with local AHJ to see if they have policy/rules on this item.

First consideration is the location of the unit, itself. Return air cannot come from a closet, bathroom, kitchen, garage or mechanical room.

If the sole source of return air is in the same room as unit, the return source must be located more than 10 feet from the unit.

If this unit were not in a “room” but was in an open and unfinished basement, I think it would be okay. If it were not, I would write it up.

In the Pic I see a supply air grill top left side, in the bottom right side I see a water heater. Does not matter if it is the sole source or not air is just like water takes the path of least resistance. That return air grill on the plenum is going to be creating substantial velocity noise will short circuit air flow from the supply grill. Create a back draft on the hot water heater. I see nothing Okay about that install would write it up every time.

Return air grills on the return air plenum’s **solves no problems;-) **

The same goes for CA.

I RED-FLAG all return vents in the same room as the furnace.

Direct-vent or not…

I have been writing them all up. I am just wondering if the HVAC guys don’t think it matters anymore when using a direct vent furnace. Thanks, Ken

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cbottger saw a natural draft water heater in the same room or area…then the return will/may cause a problem, so these HVAC guys have to be careful, re-train on managing house pressures, etc.