Discharge Hood with Positive Closure Dampers
When a closed circuit cooler is used in a water-to-air heat pump system or in certain process cooling applications,
a method of reducing the heat loss during idle periods of wintertime operation may be required. For these cases, an optional
discharge hood with positive closure dampers and damper actuator is available.
The discharge hood with dampers is designed to minimize the heat loss from convective airflow through an idle
cooler. Further reductions in heat loss may be obtained with the addition of insulation to the hood and casing,
minimizing conductive heat losses. Insulation may be factory installed on the hood and casing or field installed
by an insulation contractor.
The discharge hood and dampers are constructed of hot-dip galvanized steel. Hoods are equipped with access
panels to facilitate maintenance of the eliminators and water distribution system. The dampers, damper actuator
and linkage are all factory assembled. Actuator controls and wiring are field supplied by others. Damper actuators
require 120 volt power supply.
The system control sequence should provide for dampers to be fully open before the fans are running and closed
when the fans are off; the damper actuator must be interlocked with the temperature control system for this purpose.
See
ATWB catalog (pg. 55) or contact the factory for heat loss data. Table ratings are based on 50°F(10ºC)
water in the coil, -10°F(-23ºC) ambient and 45 MPH(72 kMPH) winds (fan and pump off).
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