Dual Duct Constant Air Volume Air System
The dual duct system constant air volume air system supplies air in two separate runs of duct to various mixing boxes throughout the building.
One air supply duct is called the hot deck and the other the cold deck, with take offs to each mixing box located in the ceiling space.
Zone thermostats sensing the space temperature, operate a damper in the mixing box or boxes to regulate the temperature of the mixed air supplied through the diffusers to the area.
The return air fan which draws air back from all the zones, provides the return link in the air circulation.
Dual Duct System Components
The conditioned air supply system is comprised of the following components:
- Return Air Fan
- Mixed Air Dampers
- Min. Fresh Air Damper
- Prefilter Section
- Preheat Coil
- Preheat Coil Circulating Pump
- Supply Air Fan
- Hot Deck Heating Coil
- Hot Deck Heating Coil Circulating Pump
- Hot Deck Gas Fired Burner Section
- Cold Deck Cooling Coil
- Cold Deck Cooling Coil Circulating Pump
- Direct Expansion Cooling Unit (Evaporator)
- Packaged Refrigeration Unit (Compressor and Condenser)
- Humidifying Section
- Hot Deck Air Filter
- Cold Deck Air Filter
- Zone Mixing Boxes
- Air system Automatic Controls
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