heat or cold to or from Air in air conditioning system
In general there are two methods of transferring heat or cold to or from an Air conditioning system these are Fin and two coils and air washers.Fin and two coils are widely used for cooling air with cold water or refrigerants and for heating air with steam or hot water they owe their popularity to their relative compactness and the ease with which they can be installed.
When the water or refrigerant in the coils is at a lower temperature than the dew point of the entering air moisture will be condensed out of the air thus coils can be used for de-humidification as well as for cooling the duration of air passing through the cross-sectional area of coils that is the area perpendicular to the direction of airflow is usually based on an air velocity approximately 500 to 700 fpm although higher velocities are sometimes used.
the friction loss.
Hence the power needed to move the air through the coil is increased for this reason to Maximum air velocity through coils is usually limited to about 700 fpm on most cooling installations from 4 to 10 rows of tube are required over the cross-sectional area for either coils or air washes in approximately the same the depth required for coils is considerably less than the depth required for air washers and air washer having the same capacity as an 8 row coil 20 inch deep would be from 7 to 9 feet long.
The humidifying air are made and two general classes in one type chilled water or brine circulates through the tubes of the coil with air flowing over the fence attached to the outside surface of the tubes the other type is generally known as dx-4 direct expansion and this coil refrigerant evaporates inside the tubes while air flow over the fins fins are usually mechanically bonded to the outside surface of the tubes in the same manner as coils using water or brine has the refrigerant several types of coil using water as the cooling medium or Illustrated.