All-Water Systems
All air-conditioning is achieved by water-air heat exchanger at terminal. Examples:
• Fan-coil
• Unit ventilator
• Radiant panels
Fan coil units do not provide ventilation.
Unit ventilators draw air in through walls (see schematic at right)
Outdoor air
This system may be only for heating: O
Fan coils have no OA, while unit ventilator has OA intake. Infiltration is a mechanism that provides fresh air in spaces with no OA.
Advantages: small/no plenum, individual control, and simple retrofit.
Disadvantages: high maintenance, condensate in occupied space, poor humidity control, and mediocre ventilation control.
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FIGURE 14.9g A cooling tower cools water by evaporation. This "cooling" water is then used to cool the condenser coil located elsewhere. |
120° MOIST AIR
Posted in Fundamentals of Heating. Ventilating, and Air-Conditioning