Working of Room Air Conditioner

Consider a Room to be maintained at a constant temperature of 25*C. The air from the room is drawn by the fan and is made to pass over a cooling coil of the evaporator, the surface of which is maintained at a temperature of 10*C. After passing over the coil, the air is cooled to around 10*C before being supplied to the room at 25*C by the fan. In the cooling coil, the refrigerant, R-22 or R-134a enters at, say, 5*C and evaporates absorbing the latent heat of vaporization from the room air.

The Refrigerant vapor from the evaporator is compressed to high pressure before entering the condenser where the atmospheric air at about say, 45*C, in summer is circulated by a fan. After picking up the latent heat of condensation from the refrigerant, the air is thrown back to the atmosphere, say, at 55*C. The high-pressure liquid refrigerant from the condenser is reduced to the low - evaporator pressure by passing through the expansion device (Capillary tube) before entering the evaporator. The cycle repeats itself.

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Mechinopedia For Mechanical Engineers

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