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how to install an air conditioner in the wall

I need some ideas, for my sis`s house. Her husband has passed away but he had put an air conditioner in the window ,but packed it with foam all around it. When my sis asked me to look at it I found the foam was holding water when it rained and running into the woodwork under the metal siding. The wood is so bad I have to ripped the whole bump out out and rebuild. Im putting 2 new windows in and AC between. The siding is 8 inch horizontal and I`m using plywood,wrap and 4 by 8 primed sheets. How do I seal between the siding ridges, and the flat sheeting? Is J channel the only thing, and what can I use to seal around the AC so it won`t leak. I can use any ideas . This is a big project for me, since my sis can`t hammer a nail. Thanks for any ideas Sandy

Re: how to install an air conditioner in the wall

First, vinyl, aluminum, and steel siding are cosmetic not weather seals. You need to cover the sheeting with house wrap or felt which fold over the openings and provides the water seal.


Re: how to install an air conditioner in the wall

Yes I have plywood, house wrap and the primed 4 by 8 sheeting. But I`m not sure what to use around the air conditioner. Something that will seal but not hold water.

Re: how to install an air conditioner in the wall

You have to begin from the INSIDE of the house.

Most thru the wall ACs have an external metal sleeve that is installed from inside the house, in the wall.

Start by removing the interior sheetrock or inside wall covering with a utility knife from the spot you want to have your AC positioned.

You then install 2 X 4 or 2 X 6 studs to frame in the ac hole, to the size so that it takes the AC metal sleeve; a small drill bit is then used to cut 4 holes at the corners of the exterior sheathing & siding (from inside the house).

You can then go outside to cut a precise hole in the exterior siding, connecting the 4 drill holes, so that the metal sleeve can be pushed all the way thru to the outside---the sleeve has to be tilted slightly downward to the exterior, so that the water condensate from the AC when it's running will drip out the outer edge of the metal sleeve.

The sleeve is caulked around the 4 sides from the outside with silicone sealer. and secured to the new 2 X 6 or 2 X 4 members with bolts---sometimes 2 small stainless steel or aluminum brackets are installed on each lower external side to provide more support for the AC.

Finally, the AC chassis is lifted & slid into the metal sleeve from inside the house & slid into position.

See the site mentioned below for photos/diagrams of the process, along with the tools needed; they recommend you install the AC under one of the windows to save time & work, because the framing for the window (header) is already in place, but you can place it between the windows if you choose.

You have to run a dedicated elec. line either 220 or 120v, depending on what the AC requires, along with the proper receptacle.

Google "installing an in-wall air conditioner" to get an illustrated link at creative homeowner for this installation.

For additional explanatory sites, Google "installing a through the wall AC"

Re: how to install an air conditioner in the wall

Thanks for the help. I really appreciate it,and was not sure if I should also uses any seals like I put around the doors, Or if that would hold water. Thanks Sandy

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