Types of Through the Wall Air Conditioners

Through-the-wall sleeves support heavy units.

Through-the-wall air conditioners are versatile and practical choices if you don't have a window or you don't want to a unit obstructing and interfering with your window. These units provide efficient cooling and some styles have enough capacity to cool an entire home. If you're purchasing a new unit instead of replacing a unit into an existing hole in the wall, it's best to have the unit professionally installed.

Basic Wall Mount Air Conditioners

Basic wall mount air conditioners are essentially the same as window versions that give you the option of installing the unit in the wall. Like their window unit "brothers," they vent heat and humidity from inside rooms to the outdoors while fans blow and circulate cool air inside. You can to carve a hole into the wall that's big enough to accommodate the wall air conditioner. Side panel "sleeves" brace the unit's weight to keep it from falling. Some units also use brackets mounted on the exterior wall for additional support.

Slide-Out Chassis

Slide-out chassis air conditioners have built-in sleeve braces so the unit consists of one piece. These wall air conditioners have air vents that look like louvers on the sides and on the back, which vent and exhaust the warm air outdoors. The all-in-one construction makes them adaptable for use in walls as well as windows. Slide-out chassis air conditioners are most appropriate for thinner walls, no more than 8 inches thick.

Through-the-Wall Sleeves

These units are built for tougher applications, such as walls that are thick and those made of masonry materials. You can tell a through-the-wall unit by the look of its sleeves and how the air conditioner vents exhaust. The sleeve units have an exterior grill attachment and the air conditioner vents from the back only, where slide out chassis units vent from the sides and the back. Through-the-wall sleeves are selected to fit the specifications for the wall and are purchased separately from the air conditioning unit.

Packaged Terminal Air Conditioner (PTAC)

PTAC units are most often found in commercial settings such as hotels and offices, although they can be used in homes as well. They're popular and practical choices because they provide both cooling and heating in one self-contained unit. The compressor pumps refrigerant to cool coils inside of the unit, drawing out heat and humidity from the room and exhausting it outdoors. When the heat function is turned on the compressor reverses its procedures and uses the coolant to heat the coils and push the warm air into the room instead of venting air outdoors.

Ductless, Mini-Split Air Conditioners

The benefit of ductless wall air conditioners is that you can bypass the need (and expense) of installing a duct system in walls and crawl spaces. This makes them good choices when you want the power of central air conditioning. They can cool the same amount of square footage and "zones," or different rooms, within a home. With a ductless mini-split system, the compressor unit is housed indoors. It looks a lot like a big indoor air conditioning unit. If you use a ductless system to cool multiple rooms and zones, you'll often need additional compressors. The compressors are connected to an outdoor condenser that looks and behaves like the condenser for a central air conditioning system. Ductless mini-split systems can be mounted on a wall and even on a ceiling.

References

• Energy Savers: Ductless, Mini-Split Air Conditioners
• AJ Madison: Install in a Wall
• Furnace Compare: Package Terminal Air Conditioners (PTAC)
• Bob's Heating and Air Conditioning: Window and Through the Wall Units -- Benefits and Disadvantages
• Ductless Guide; Sizing a Ductless Air Conditioner; Shawn Mack; January 8, 2009