Help me insulate my air conditioner!

January 27, 2009 10:17 AM

lI have a through-the-wal air conditioning unit. How do I stop the cold air outside from coming in through the cracks?

I have a Friedrich WallMaster through-the-wall air conditioner that's great during the summer, but leaves my apartment exposed to the elements during the winter months. It's one of those sleeve models, so the back is just a grate that lets the cold air flow in with only the structure of the AC to stop it. The unit came with this foam wadding to help seal the edges, but it just doesn't do the trick. Is there some other insulating practice that I just don't know about?

THANKS!

posted by kmtiszen to Home & Garden (8 answers total)

Go to the hardware store and get removable sealant. It usually comes in clear or white and you can peel it off later when you move or if you need to swap out or remove the A/C unit. If you're unsure what to get, explain it to the hardware store guy or girl and I'm sure they can point you to the perfect thing.
posted by amanda at 10:22 AM on January 27, 2009

Are you looking for some kind of a cover for it? Something that would go over the outside of the unit and prevent the cold air from just coming in?

Its hard to tell if you are asking about the grate or the cracks. The cracks, as amanda notes, can be taken care of by some sealant. The cover should be pretty easy to find (found http://www.accovers.com/ on Google).
posted by fenriq at 10:28 AM on January 27, 2009

I just duct tape a bunch of blankets over mine.
posted by nomisxid at 10:53 AM on January 27, 2009

If you don't want to use sealant, you can get foam weatherstripping and use a flat, dull blade (like a drywall spatula) to push it into the cracks. If you do decide to use sealant, try like hell to keep it off your hands and definitely don't get it in your eyes... that stuff is an incredible mess to clean off.
posted by crapmatic at 10:56 AM on January 27, 2009

Also I just now noted where you said foam strips don't work -- but you may want to make sure they're pushed in properly. Otherwise you can try to cover the AC unit on the outside with a big, thick garbage bag to help form a barrier.
posted by crapmatic at 10:58 AM on January 27, 2009

You need an AC cover it sounds like.
posted by caddis at 11:16 AM on January 27, 2009

The foam is really to keep dirt and water out and to not let too much hot air in during the summer. In the winter you need to seal it up with a sheet of plastic and some tape. Just put it over the unit and seal the edges until there's no more breeze. Duct tape and garbage can bags work great. Do both the exterior and the interior. If you cannot get access to the exterior or its unsafe to do then just do the interior.
posted by damn dirty ape at 12:15 PM on January 27, 2009

For something a touch more aesthetically pleasing than garbage bags, you could use some weather sealing plastic sheets on the inside of your apartment.
posted by megamanwich at 6:56 PM on January 27, 2009