Return to the Heating & Air Conditioning Forum | Post a Follow-Up

How to add cold air return in an interior wall?

Posted by stash-hdy (My Page) on
Fri, Jul 15, 11 at 22:08

I have a room over the garage and need to move the cold air return. Right now it�s in the ceiling right next to the furnace outlets. I would like to move it down to floor level using the cavity between the studs as the chase. How do I modify the cavity to make it usable as a cold air return? Any links with pictures would be appreciated.

Follow-Up Postings:

RE: How to add cold air return in an interior wall?

So I guess the unit is in the attic and the supply and return vents are both in the ceiling and you want basically the same result as a basement install just flip flopped.

The return area per cavity is not spectacular at around 50sq inches which is enough return area to roughly compensate for one 6" duct supply. The best results will come from having return air in every room other than kitchens and bathrooms which doesn't sound like an option.

The next best is what you are working to achieve. The closer the return is to the center of the living area the better. You can build it out into the corner of a room or closet or right in a room and use the bumped out area for pictures or put a couple corner shelves on the sides. there are a lot of ways to make it look like it wasn't an afterthought.

The garage would work and be much better than what you have now but you might look into an option to add two somewhat smaller returns using some other area of the house to make the air actually circulate to multiple areas. Be creative.

As far as sealing the cavity it is a pain going in with duct mastic on a brush and different sized sticks to brush it in the corners through the small entrance hole to seal the cavity without panning it with metal. This is one other case of using your imagination and what you have on hand including using your hand. The good news is if you build the duct/ducts out you will have access to seal as you build.

The comfort level with one return like you are planning will increase greatly and two in different areas would make it a lot more even.

There is so much that depends on the size of the home and layout. A rather square home with one central return will have a whole different comfort level than a longer ranch style.

RE: How to add cold air return in an interior wall?

I agree with the above. One return using a wall cavity will almost certainly not be enough return compared to what you're pulling now, hurting efficiency and lifespan of the equipment. If you want to use the wall cavities, you'll need multiple returns.

RE: How to add cold air return in an interior wall?

Thanks, I do have a storage room behind the far wall, could build out a bump out behind the wall for the cold air return. Question, is the 50 sq inches for each room or for the cooling unit itself?

RE: answered my own question

It's 50 sq inches per room, should have thought about what makes up 50 sq. inches.

RE: How to add cold air return in an interior wall?

One stud cavity is approximately 50sq on a 16" stud wall. If you plan to do individual returns per room make sure there are no switches in the cavity area and be aware of where the outlets are as their may be a wire going across the wall to the next outlet. I would pick the spot and partially open up the return vent area and either take pictures of the interior of the cavity through the hole or use a camcorder to make sure there are no surprises. If there is a wire crossing for the outlets and you can reach it be sure to seal it. I am not sure if a crossing wire is a code issue but I know that switches or outlets in the return path is a code issue most places and should be avoided. In the electrical department of most home depot and lowes they have long drill bits up to 6' long which might allow you to reach up to the top plate to locate where to start opening up in the attic. This is totally unsafe if you don't get a visual of what might be in the cavity and be sure to go in the attic and make sure there is nothing to worry about or deal with from up there.

I would have to say the easiest way would be to pick two spots and bump out the wall and that way you can open the spot and see what you are doing and you would only have to do it in two spots.

RE: How to add cold air return in an interior wall?

Thanks again, I will do the bump out in the storage area. I did look for a location and will most likely have only one. The other possible location has an outlet that would be in the way.

RE: How to add cold air return in an interior wall?

It might not be perfect but it will be a whole lot better than everything on the ceiling. I did a bump out into a closet and it was a whole lot easier building and sealing that one than trying to seal the existing ones that were in wall cavities.

 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!

Return to the Heating & Air Conditioning Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Please review our Rules of Play before posting.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.

Learn more about in-text links on this page here