An air conditioning, or HVAC&R, system is composed of components and equipment arranged in sequence to condition the air, to transport it to the conditioned space, and to control the indoor environmental parameters of a specific space within required limits.
Most air conditioning systems perform the following functions: 1. Provide the cooling and heating energy required
2. Condition the supply air, that is, heat or cool, humidify or dehumidify, clean and purify, and attenuate any objectionable noise produced by the HVAC&R equipment 3. Distribute the conditioned air, containing sufficient outdoor air, to the conditioned space 4. Control and maintain the indoor environmental parameters–such as temperature, humidity, cleanliness, air movement, sound level, and pressure differential between the conditioned space and surroundings—within predetermined limits
Parameters such as the size and the occupancy of the conditioned space, the indoor environmental parameters to be controlled, the quality and the effectiveness of control, and the cost involved determine the various types and arrangements of components used to provide appropriate characteristics. Air conditioning systems can be classified according to their applications as (1) comfort air conditioning systems and (2) process air conditioning systems. Comfort Air Conditioning Systems
Comfort air conditioning systems provide occupants with a comfortable and healthy indoor environment in which to carry out their activities. The various sectors of the economy using comfort air conditioning systems are as follows:
1. The commercial sector includes office buildings, supermarkets, department stores, shopping centers, restaurants, and others. Many high-rise office buildings, including such structures as the World Trade Center in New York City and the Sears Tower in Chicago, use complicated air conditioning systems to satisfy multiple-tenant requirements. In light commercial buildings, the air...