Vibrating noise from bathroom exhaust Fan

Cleaning out some storage and came upon this transformer, not sure why I saved it. Its to a Trane HVAC system. To test if it is working (and thus I would continue to keep as I'm sure it's related to my Trane HVAC) would I just connect line voltage hot to the 115v tab and the neutral to the upper "C" tab then measure for 24vac on the bottom two? If so, can these show 24v yet still fail under a load? Again, not sure why I'd kept this if I replaced it. (Memory fading....) [img]https://cimg4.ibsrv.net/gimg/www.doityourselft.com-vbulletin/1512x1512/copy_53198bb87de1ea77f13bb32c8903ad901b401afe.jpg[/img]

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. [b] Is there any reason to keep these active? [/b] 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. [b]Does it seem reasonable to remove these cold air return vents?[/b] 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! [img]https://cimg9.ibsrv.net/gimg/www.doityourselft.com-vbulletin/2000x1504/20221220_200203_bdc5e8138df3cab7b976d21d44132e62c97045fa.jpg[/img] [i]Existing ceiling vents. Rectangular duct is not heat but cold air return.[/i]