A room air conditioner is generally considered to be a unit suitable for placement in any particular room. The room in question may be in an office, a home, or a small shop. Room air conditioners are usually classed according to their design and method of installation (such as window units and portable units).
As the name implies, window units are installed on the windowsill. Portable units can be moved from one room to another as conditions and occupancy dictate. The advantages of this type of air conditioner are the relatively low-cost summer cooling in the room selected, as well as the portability and ease of installation. Figure 5-1 shows a typical window air-conditioning unit. When properly installed, sized, and serviced, the room air-conditioning unit gives a large measure of comfort, free from irritating exhaust that accompanies sweltering hot spells and extremely high humidity.
The window-type air conditioner may be divided into three functional systems: electrical, refrigerant, and air path. The electrical system consists of the motor-compressor, unit control switch, fan and fan motor, starting and running capacitors, starting relay (when used), thermostat, and necessary wiring. The refrigerant system consists of the compressor, condenser, drier-strainer, capillary tube, evaporator, tubing, and accumulator. Some systems have the refrigerant flow controlled by means of an automatic expansion valve instead of the conventional capillary-tube method. The air path consists of an air discharge and intake grille, air filter, vent door, vent controls, and so on. Figure 5-2 shows the component parts of a window air conditioner.