Document JN88mmO6YgMY3Jk6Vjgrxb0gv

Heating Ventilating Air Conditioning Guide 1939 2. Central unit with preheating coil, washer and reheating coil (refer to Fig. 2). fi. system is widely used for winter conditioning on larger installations and summer co0 ditioning is accomplished by using cold water in the washer. COn" 3. Blow through system with heating and cooling coils and mixing dampers (refer Fig. 3). This system is used where several different zones are served from one centr I system and the conditioning of the entering air for each zone is determined ly mix;3 varying quantities of air after passing through the conditioner. ~g Fig. 1. Central Unit with Coils and Sprays Central Systems for Comfort Air Conditioning Fig. 3. Blow Through Systems with Coils and Mixing Dampers 4. Central outside air conditioning units with unit recirculating conditioners (refer to Fig. 4). This system is used on installations having large zones requiring independent control to meet local requirements for office and apartment buildings, hotels, etc. 5. Central conditioning unit either washer or coils with booster reheating coils (refer to Fig. 5). This system is used for special zone arrangements where there is considerable variation in requirements of different zones such as hospital operating rooms or an auditorium served in conjunction with office and store cooling systems. An entirely different method of dehumidification is used in some installations where the extraction of moisture is accomplished by methods of adsorption or absorption. Materials which are commonly.used for these ..Fig. 5. Central Unit with Either Air Washer or Coils and Booster Coils