Window air conditioner installation question

I want to buy a portable air conditioner unit. Problem is , my windows are horizontal sliders rather than the vertical sash windows these things are designed for. Therefore there is no way to fill the opening above the unit in the window frame. Any ideas?

How much of an issue is security?

Cut a piece of plywood to size. Paint some pretty flowers on it.

There are vertical-mount window air conditioners available, and some companies sell installation kits to adapt their air conditioners to different windows. I saw this at the Wal-Mart site, for instance.

I used to install window a/c’s for a store. I carried 3/16 fiber board just for your problem. Cut it to fit, and run a bead of putty around the opening, and you’re done. I think we are talking a small area to cover, SKYBUM, and security would’nt be an issue.

Thanks to everyone. This post was especially useful.

I prefer to mount “window” type A/C units in their own hole, and leaving the windows alone.

Of course, this is not generally an option for apartment dwellers or renters.

But for a homeowner, it’s not a hard job to cut a small opening in the wall, frame it in with some 2x4s, add some metal flashing and caulk, and have a securely mounted A/C that is less stealable and less of a security risk from burglars, etc.

Handy with tools? Yep, thanks for asking :smiley:


It might not be that simple, if your ac is wider than 14 and a half inches you will have to cut thru a load-bearing stud (you are putting it thru an outside wall aren’t you? and it is a given that an outside wall is load bearing … Yea there are exceptions) which requires jack studs and a header. Its hard to do all of that and not mess up a wall.

…yeh, and oh wait until the day comes, that after you have done your measuring twice, pencilled in the area that you are going to cut with a sawzall, and get four inches into your cut when the sawing comes to an abrupt halt, and you hear and smell gas from an… unknown to the homeowner…gas line going up the side of the house in between the studs. Was not a fun day. :eek: