I am converting an old drop 2x4 fiberglass ceiling in my basement rec room with 2x2 rigid tiles and LED recessed lights. There are two diffusers in the ceiling of the rec room and I have always kept the dampers closed. I just figured these two vents were for heat (and AC) since they were on the ceiling and there were adjustable dampers. The ceiling vents are actually part of the cold air return. I think it was a prior mistake?? It'll be a pain to adjust the vents lower to fit the rigid ceiling tiles and then cut the tiles to fit the dampers properly. Not to mention they don't look great. Is there any reason to keep these active? The ceiling tiles will be be easier to install and look better, and besides the dampers have been closed since we moved in 6 years ago.

The basement is about 3/4 finished with a heat vent in a small bedroom and bathroom. The house was built in 1951 and someone added the ceiling grid I'm guessing in the 80's. There are only two heat vents in the basement for a small bedroom (not used currently) and small bath, but both vents are kept closed. The basement is warm from the hot water heating system flows around the basement wall perimeter and that serves the 2nd floor. The 1st floor is serviced by forced air.

I'm thinking someone thought this rectangular duct was heat and decided to connect two round registers to heat the main basement rec room, and this effort was just a waste. When the blower kicks on the cold air returns on the 1st floor supply the furnace but there is still some air flow down the staircase. Based on the air flow I'm assuming there are enough leaks in the cold air return and inflow at the blower in the basement, therefore additional cold air returns in the basement are not helping anything.

Does it seem reasonable to remove these cold air return vents? I could remove the start collars (hopefully that's easy to do) and close off with a sheet metal patch. This will make ceiling install easier and look better as well. Thanks for any feedback!


Existing ceiling vents. Rectangular duct is not heat but cold air return.

 

Maybe they were put in to recycle the heat from the furnace.
Maybe they were put in to recycle the cold air in the summer when the A/C is on.

I don't see why you couldn't close them off.
I'm guessing there are enough other returns upstairs ?
Sometimes extra returns are installed if there is not enough flow from the main floor.

 

There are cold returns on the 1st floor in each room. There is a little noticeable air flow that wants to pull the door for the stairs shut when the furnace kicks on. Since the furnace is pulling air already and the basement dampers have been shut, there really wouldn't be a change.

It just seems odd having an adjustable damper on a return, so I figured it was an hvac install mixup. I'll definitely remove the one problematic vent since it is nearly on top of the T grid and no good way to fit tile nicely.

Thanks for the feedback Pete!

 

And no ill effect so far?

Then I would think your good to leave them closed or seal them off permanently!

 

I'm always leery of closing returns but if you've effectively had them closed for a while without seeing any negative effect, you're probably fine to do so permanently.

 

I'm going to permanently close one of them and adjust the other vent to fit the new ceiling tiles (and remain operational with the damper as needed). I understand being leery with closing the returns since I don't like removing a device that gives me an options (the one is just in a terrible location with regards to the ceiling grid). My thinking is that opening returns in the basement will reduce heat (circulation) on the 1st floor where we spend most of our time and want more heat. The only positive of the basement return would be to capture and recycle heat produced from the two boilers and hot water supply pipes running arounds the basement perimeter. The same would be true for recycling cool air in summer.

What I really need is an actuator to supply outside air to both boilers when they are both burning along with the hot water heater. The house normally has negative pressure which is noticeable when I try to burn wood in the fireplace. The 1951 construction including an outside vent to the furnace room. It's been plugged but talking to the home inspector several years ago it seemed to make sense to add a passive vent to allow it to open when additional air was needed in the furnace room. This is a different topic than the cold air returns but part of the struggle to evenly heat an older home efficiently.