Quest IQ Compressor Wall OMM
16
September 2020
Sequence of Operation
The HVAC system
’s
ventilation system establishes the required airflow through the HVAC system. The control
system compares air temperature and humidity to their desired values (set points) and proceeds to dehumidify,
cool or heat the recirculating air.
Set Points
The control system is constantly adjusting HVAC system operation to achieve and maintain said parameters within
couple degrees/percent of the set point.
•
Grow room temperature and humidity set point may vary based on the pre-
set schedule (“lights on”,
“lights off” etc.).
Note:
Refer to the HVAC system
’s
main label for the design value of control parameters.
Ventilation
The
main blower
runs continuously, establishing required airflow. The main blower speed is pre-set via adjustable
variable signal.
HVAC system can control the
outdoor air
intake (OA1) damper and the external
minimum exhaust fan
(EF1) (to
bring outdoor fresh air in and to directs portion of return air outdoors, respectively).
•
If such option is used, exhaust fan speed would be controlled, like the main blower, via adjustable (pre-set)
variable signals: the exhaust fan speed may vary depending on scheduled ventilation mode.
•
Note
.
Externally installed Exhaust Fan(s) and Outdoor Air damper(s) could be also controlled by the HVAC
system control system for Exhaust/Purge purposes.
Space Heating
When premise air temperature drops below the set point, the HVAC system control system issues a call for Space
Heating Mode and engages space heater (electric heater, hot water coil with valve, gas boiler etc.) by sending space
heating signal, respective to space heater control type - on/off, variable (0-10VDC), etc.
Air Conditioning and Dehumidification
When premise air temperature goes over (exceeds) its set point, the HVAC system control system issues a call for
Air Conditioning Mode. Respectively, when premise air humidity goes over (exceeds) its set point, the HVAC
system control system issues a call for Dehumidification Mode. In some instances, these calls may co-exist.
To execute Dehumidification or Air Conditioning (Cooling) mode, control system, depending on current conditions,
would resort to available means of cooling or dehumidification.
