Operating instructions
12 
SET VENTILATION 
The  SET VENTILATION mode is used to set the number of desired stages of the vent openings, the desired 
position of each stage, the actual total opening time for the vent itself, and to let the system know if there is a 
safety time delay in the vent control panel being used. The programming also allows the vent to be linked to a 
cooling stage or to override input if desired. The dehumidify functions of the vent, both immediate and timed, are 
programmed here. This mode also is where the vent temperature differentials and temperature stage separations 
are set. The vent system timing will be set here. The vent temperature may also be adjusted throughout the day 
according to the solar intensity. An adjustable ramp time can be entered in order to allow for gradual temperature 
changes when changing modes.  A reference temperature can be entered here. The reference temperature will 
adjust the vent maximum position in relation to another sensor reading. A typical use for the reference 
temperature selection would be to adjust the vent maximum opening based on the outdoor temperature. 
1. Enter the SET VENTILATION mode. 
2. Use the PRIOR-NEXT switch to advance to the desired item to set. 
3. Use the VALUE switch to toggle between desired choices that the system has internally provided. 
Open Vent 1 
In (4) Positions 
Set the desired number of ventilation stages here. The system can operate the vent in up to eight separate 
stages. If the output is connect to a pad vent system, then enter “PAD VENT”. The Growmaster Procom will now 
open the pad vent with the cooling stages as they turn on. 
Vent 1 Pos 1 
10% Open 
Set the desired percentages of opening here for each stage. The final stage will always be set to maximum vent 
position.
Vent 1 Max Pos 
(100) % Open 
Set the desired maximum position for the vent. 
Opening Time 
Vent 1 3:00 
Set the actual time that the vent takes to run from its fully closed position to fully open. This time is critical, as the 
system will use this to determine correct openings. 
Safety Delay for 
Vent 1 (5) SEC 
If your vent control system is equipped with a time delay relay that protects the vent against false reversals, enter 
the number of seconds here. If you are in doubt whether your system has a time delay, simply manually energize 
the vent. If the vent starts to move immediately, there most likely is no time delay protection. You may choose 
NONE as one of the choices. 
Link Vent 1 to 
Cooling Stage (NO) 
Use this feature to link a set of vents to a particular cooling stage if desired. A possible use for this would be in the 
event that roof vents, as well as active cooling such as exhaust fans are in use. This feature will allow the user to 
link the roof vents to close to a low position when the cooling stages are active. This would allow the air to be 
drawn across the entire range and not through the roof vents by the exhaust fans. This setup is not applicable to 
“PAD VENT”. 
Vent 1 (Closed) 
on Cool Stage 1 
If a link is made to a cooling stage, the system will then ask what vent position during that cooling stage. 










