How to seal AC hole in the wall


  #1  
Old 07-15-11, 09:04 AM
N
Member
Thread Starter
Join Date: Jul 2011
Location: USA
Posts: 4
Upvotes: 0
Received 0 Upvotes on 0 Posts
How to seal AC hole in the wall

Hi all,
I had a contractor install a split AC unit and they didn't seal the hole in the wall. On top of that, they drilled the hole so that it is higher in the exterior than in the interior of the wall. As a result, we had some rain and heavy winds and it rained inside our living room.

I called the contractor and they said they will fill the hole with polyurethane foam. Is this a good choice? (I don't trust them anymore). We plan to move in less than two years and take the split AC unit with us, and I'm concerned that if the hole is filled with foam, it will be hard to remove. Are there any better alternatives?
Thanks.
 
  #2  
Old 07-15-11, 09:54 AM
Tolyn Ironhand's Avatar
Group Moderator
Join Date: Nov 2007
Location: United States
Posts: 14,499
Received 916 Upvotes on 774 Posts
Duct seal will work pretty well and is not permanent. If the hole is big you might need some backer rod or other foam.
 
  #3  
Old 07-16-11, 01:42 PM
N
Member
Thread Starter
Join Date: Jul 2011
Location: USA
Posts: 4
Upvotes: 0
Received 0 Upvotes on 0 Posts
The hole is about 4 inches in diameter and 11 inches deep.
 
  #4  
Old 07-16-11, 02:35 PM
Gunguy45's Avatar
Super Moderator
Join Date: Dec 2007
Location: USA
Posts: 19,281
Received 8 Upvotes on 8 Posts
Foam the interior...or even all the way to the exterior...then fabricate a cover for the exterior and caulk or use duct seal around the lines. What is the exterior surface made of?

Getting the foam out is easy...it's like styrofoam almost.

Why in the heck did they make it that big? Most only need about a 2" hole.
 
  #5  
Old 07-17-11, 05:17 AM
N
Member
Thread Starter
Join Date: Jul 2011
Location: USA
Posts: 4
Upvotes: 0
Received 0 Upvotes on 0 Posts
Thanks. The wall is made of brick with an exterior layer of plaster (I think). The exterior hole is kind of hard to reach, they'll have to hang from the roof or something.
 
  #6  
Old 07-19-11, 03:44 AM
N
Member
Thread Starter
Join Date: Jul 2011
Location: USA
Posts: 4
Upvotes: 0
Received 0 Upvotes on 0 Posts
The "contractor" came and put in polyurethane foam *from the outside*. The foam is actually protruding out the hole in a big mess about 2 inches thick, not a pretty sight. I don't think it goes very far in but I can't tell for sure. He didn't remove the unit to do the job.

I hope this works. The guy was just hanging out of my third floor window with both feet on the windowsill with no harness, hanging with one hand and putting foam with the other. I'm surprised he actually didn't fall down.
 

Last edited by notuno; 07-19-11 at 03:45 AM. Reason: typo
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: