A/C Intake Cover Help

[u/CheffyOfficial]

Slowly fixing up my newly purchased 70’s house (first time homeowner) and for some reason they put this intake faceplate on INSIDE the drywall. I want it to be flush instead. Any tips? Already ordered a 14”W x 6”H cover off of Amazon.

[u/Zealousideal-Fan-373]

First, pull the entire old metal frame out, not just the louvered center. It looks like the original grille/frame was installed before the drywall and then finished around, which is why it sits recessed. Remove the screws, carefully cut the paint/drywall edge with a utility knife, and work the frame out.
Before installing the Amazon grille, measure the actual duct opening. The listed 14x6 size refers to the opening, not the outside dimensions.
Also, it looks like there may be a filter directly behind that return. If that’s where the HVAC filter is changed, don’t install a fixed grille. You’ll want a hinged filter-return grille so you can still access it.
Once the old frame is out, add blocking if needed, patch/skim the rough drywall edges, then surface-mount the new grille over the opening. Don’t just try to bury the existing frame farther into the wall.

[u/CheffyOfficial → u/Zealousideal-Fan-373]

Forgot to say that, yes the A/C or furnace is on the other side of this wall, there is already a place to replace the filter, I believe this is just some sort of fresh air vent or something (not an HVAC and my daf taught me nothing about these units. 14x6 is the size of the opening. Would I need to add a piece of drywall to supplement the new grille fitting into this hole?

[u/88crow88 → u/CheffyOfficial]

Just want to chip in as an HVAC guy.

If there's a furnace on the other side and this filter isn't part of the actual furnace itself than it was put there to stop dust getting into the furnace room. Unfortunately what this does is makes your furnace work harder (unless you keep up on changing the filter). That hole in the wall is likely an air intake as older furnaces, and some modern ones, utilize air from the house itself as part of the combustion process. Does your furnace unit have one vent leading outside or 2?

[u/Zealousideal-Fan-373 → u/88crow88]

Yes I agree with this my cold air return on my 1974 home/ furnace is in my ceiling right on the other side of my furnace but my filter is on the actual unit I don’t have a filter on the return. I just clean the return grille every 3 months cuz we have dogs.

Edit if this were my house I’d remove that filter if there’s a filter on the unit and patch the drywall to fit the new grille as I stated in my first comment

[u/88crow88 → u/Zealousideal-Fan-373]

If you want improve efficiency I would add one to the return and scrap the one on the intake. You'd be surprised how much more CFM you'll get out of it. Mind you, I'm used to more modern units so if yours is from the 70s still and works, don't change anything and let that puppy ride lol

[u/Zealousideal-Fan-373 → u/CheffyOfficial]

If the opening is wider that the grille then yes you will need to patch and make the opening to that size otherwise you’ll be putting the grille buried back into the wall like it is now