Sterlco SBFC Series Blown Film Coolers - Manual (Page 24)

Page 24 SBFC Series Blown Film Cooling Systems
4. Set the chiller for the leaving water temperature you want,
based on the leaving air temperature you’ve selected.
You should initially set the leaving water temperature
approximately 15ºF (8ºC) below the leaving air
temperature. Adjust the leaving water temperature as
needed.
Note: Chilled air temperatures below 32ºF (0ºC) will cause
condensation to freeze on the coil, resulting in air blockage
in the coil and moisture carry-over. This can also cause
permanent damage to the cooling coil.
5. Adjust the optional 3-way valve to obtain the leaving air
temperature you selected. See Section 5-3 on Pages 27-30.
When completing a system startup, you should check the volume
of air delivered to the air ring, since it is the amount of air and the
air temperature that determines chiller load. One method of
determining the volume of air is to measure the air velocity at the
blower inlet. Measure this volume using an air velometer; it is an
instrument that uses a rotary wind vane or propeller.
The number of revolutions is directly proportional to the air
velocity, and the air velocity is read directly from the read-out
meter. You’ll need to make a number of measurements to
determine the average velocity at the blower inlet. By measuring
the exposed blower inlet area, you can calculate the average flow
in cfm (cmh) of air delivered to the air ring. The flow in cfm (cmh)
of air used is proportional to the chiller load at any given
temperature.