Air Conditioner

It is called a window air conditioner because it is usually fixed in a window. The Window or Room air conditioner is used to cool a single room or a large space. It consists of the following basic parts:

Compressor
Condenser
Evaporator and
Expansion valve

The working of the window air conditioner shown in Figure, is described as under

The refrigerant vapour leaving the compressor is at high pressure and temperature. It then passes through the condenser. Outside air is drawn in by the fan and it cools the refrigerant in the condenser, the refrigerant then becomes liquid. The high pressure, low temperature liquid refrigerant enters the expansion valve. The pressure and temperature of the refrigerant drops when it leaves the valve.

The cold refrigerant from the valve passes through the evaporator (the evaporator side of the air conditioner faces the room to be cooled). The warm air from the room is drawn in by blower. The evaporator cools this air and the liquid inside the evaporator tube gets vaporized by absorbing the heat from the warm air. The cool air is again sent to the room through the opening at the top of the air conditioning unit.

The liquid and vapour refrigerant from the evaporator passes to the compressor and is compressed to high-pressure, high temperature liquid. The operation hereafter is carried out in cycle as the same manner as explained.

Due to cooling, the water vapour in air condenses outside the evaporator tube. The drop lets fall on a sloping bottom tray are collected on the outside of the air conditioner. It evaporates and helps in cooling the compressor.

Advantages of the window Air conditioner

A separate temperature control is provided in each room in which the unit is installed.

Ducts are not required for air distribution. This advantage is especially noticeable in residences in mild climates where central heating systems are not required. The advantage may not apply in cooler regions, where duet systems are necessary for winter heating, regardless of summer requirements.