Converting a window ac to a through wall unit

[LeeB]

Anybody done this before? Seems easy enough but I have very thick walls. After pulling off some siding I discovered that this house was once a pole barn construction and later had a 2x4 wall  built inside that. Between sheet rock, both wall systems, and cladding the walls are almost 12 thick. I plan to recess the unit into the wall a little so the vents will be on the outside. I bought a 23,500 btu LG window unit. Biggest through wall available is 14,000 btu. I've found other brands that say converting it is not an issue but LG says they don't have any instructions on how to do so. I'll wing it on my own and a little help from the other brands instructions. Any tips and recommendations will be welcomed.

[gasman1075]

I have installed a few that way at my friends brewery. One we use with a "coolbot" for his walk in cooler ( it was $10,000 to replace the compressor ) and the second in the fermentation room. Both LG one has been running for 4 years and the newest 24,000 BTU a few weeks. No issues with either. His walls are almost 10" thick. 

[Tom King]

Shouldn't matter as long as the condensate drains all the way to the outside.

[Raider Bill]

I use them in some of my rentals. Make sure you side vents are clear flowing and don't  believe they don't need a drain hole.

[hedgerow]

I have never installed any that way but over the years I have removed a bunch of them after installing a whole house split system. There must of been a company that built a universe brace that went on the outside of the house to hold the units up. It was made of light angle iron and had adjustable feet that went against the house siding. All of these were big 220 volt units that I took out. A lot of them had the same style brace to hold the back of the unit up. 

[wisconsitom]

Not sure if this applies, but we sawed an opening in our metal skinned shed wall, had to cut two studs out of the way, then framed the resultant opening with header, footer, sistered up studs etc.  We were installing ptac unit.  We could access side studs to screw unit sleeve to wall.  Worked great, vents and drains outside, heat, cool and fan.

[LeeB]

Got the hole framed in today and the sheathing back on. Have to put new siding on tomorrow. Still have yet to run wiring. Going to put the outlet in the ceiling above the unit. Our old ac is still working but just barely. Not looking to getting in the attic with the heat we are having right now. Supposed to be a little cooler after this weekend. Maybe I can get in there early in the morning. I'm going to install a gable vent fan while I'm up there also.

[low_48]

What I've never figured out is the efficiency of a window AC when the cold air enters the room at the top of the unit, and draws out air just below it. Doesn't that draw cold air right back outside?

[beenthere]

What I've never figured out is the efficiency of a window AC when the cold air enters the room at the top of the unit, and draws out air just below it. Doesn't that draw cold air right back outside?

What do you mean by "draw cold air right back outside" ?

[Ianab]

Generally AC units don't exchange air between inside and outside. A "window" unit isn't much different to a 2 part through wall, except it's all in one box for easy installation. 

As far as installing one in a "wall". What if you made a small "window", about the size of the AC unit?  Need to check drainage and any venting above or below the unit, and with an extra thick wall, that might be an issue. But nothing a slightly bigger "window" with some extra flashing and insulation can't fix. 

[LeeB]

As far as installing one in a "wall". What if you made a small "window", about the size of the AC unit?  Need to check drainage and any venting above or below the unit, and with an extra thick wall, that might be an issue. But nothing a slightly bigger "window" with some extra flashing and insulation can't fix. 

That is what I'm doing. 

[low_48]

What I've never figured out is the efficiency of a window AC when the cold air enters the room at the top of the unit, and draws out air just below it. Doesn't that draw cold air right back outside?

What do you mean by "draw cold air right back outside" ?

I thought there were louvers on the top of the front surface of the AC and then louvers in the center of the front with a filter over the coil. Both sets of louvers are on the front of the AC unit and it just appears that there would be some mixing of the cool dry air pushed out the top and the room air being pulled over the center louvers and filter to get blown out the back of the AC to the outside. Do they not send room air outside? I've never owned one.