I'm trying to figure out what the difference is between "through the wall ACs" and "Wall sleeve replacement ACs." They seem to be differently priced but I don't know what else the difference is. My building told me to buy a wall sleeve replacement AC (the sleeve is already there in the apartment) but I'm wondering if I can buy the cheaper "through the wall AC." Any insight?
A through the wall AC unit is more or less a window unit with slightly different mounting. The heat vents out through both the sides and back of the unit. A wall sleeve unit slides into the sleeve and vents entirely out the back. Generally wall sleeve units are used on walls greater than 8" and through the wall units are installed in walls less than 8" thick. If the sleeve is already there you'll need to buy a sleeve replacement unit.