Room air conditioners are available for installation in double-hung and casement windows. Some types can be installed in sliding windows too. Wall or window units have adjustable sides and can be set inside an open window. Wall units are installed flush into an exterior wall. The biggest energy user in any air conditioning unit is the compressor, which pumps the refrigerant through the air conditioning system to cool the room.
Room air conditioners
Window or though the wall air conditioners used for room cooling consist of three basic parts:
A hermetic compressor
An evaporator using a capillary tube refrigerant control.
Liquid refrigerant collects in the lower coils of the condenser. It flows through the capillary tube refrigerant control into the evaporator. When the unit is in operation, the evaporator is under low pressure. The liquid refrigerant rapidly boils and picks up heat from the evaporator surface. A motor-driven fan draws air from inside the room, and pulls it through a filter. The fan forces the air over the evaporator. Here, the air is cooled and goes back into the room.
During cold weather
The refrigerating mechanism is turned off.
The electric resistance-heating units are turned on.
The room air fan is turned on. The same fan circulates warm air in cold weather and cooled air in warm weather.
These air conditioners are usually connected to 240 V circuits. A control provides a choice of temperatures.
How to installing a window air conditioner through an exterior wall
Mark the opening on the inside wall. It is better to place it higher on the wall so when the air conditioner is in a window, the cold air is heavy and sinks to the floor and this gives the air a longer reach into the room.
Cut the opening with a utility knife, or a drywall cutter. Cut it back until the studs in the area to hold the unit have been exposed.
Be very careful while cutting that the electric wiring or plumbing is not damaged. It may be helpful to cut and remove the area in small pieces so that the wall cavity can be checked.
Pull out the insulation that may hide wire or plumbing. If these are in the opening area, the opening can be moved or the wires or plumbing rerouted.
Drill holes in each corner of the desired opening through the sheathing and exterior siding. Then, from the exterior, cut the hole with a portable circular saw.
Cut the studs within the opening, leaving space for the unit plus the double sill and header. The opening should be about 1/4 to 1/2 inch larger than the air-conditioner.
Remember, this is a load-bearing wall, so if the ceiling needs temporary support, block it up with several 2x4 members joined to a horizontal member next to the ceiling.
Install the framing forming the finish size of the opening and supporting the ceiling or second floor load.
Install the air-conditioner and chassis. Caulk around the sides of the opening and the cabinet.
Repair damage to the finish wall and nail a molding around the unit to give a finished look.
How to install a double hung unit
Screw the expandable panel to the window sash and sill as directed by the manufacturer.
Slide the cabinet into the opening in the window and screw to the sill and sash as directed by the manufacturer.
When the cabinet extends more than 12 inches beyond the exterior sill, braces are needed.
Install the chassis in the cabinet; secure it to the cabinet as directed by the manufacturer.