Rear Ventilating air conditioners vent out through the back of the unit, and are ideal for wall sleeve air conditioners in which the sleeve will otherwise cover the vents. Wall sleeves simplify installing an air conditioner in your wall by giving you something lightweight to work with, so that you don't have to play around with screws and drills while balancing a 100-pound air conditioner.
In order to figure out how many BTU you will need to properly cool a room, multiply the square footage of the room by 25. Then add 1,000 for each window, and 400 for each occupant. Thus, if your room is 500 square feet and you have two windows and three occupants, the total BTU you will need is: (500 x 25) + (1,000 x 2) + (400 x 3) = 15,700 BTU.
Find the perfect sleeve air conditioner. Most are Energy Star Efficient, while a wide range of cooling btu are available to fit any sized living space. Choose from Fedders, Friedrich, GE, LG, Sharp, and more.