These settings and rules are preset to typical values that will suit the majority of grow rooms, however, expert users may wish to alter them to achieve optimal performance.
Switching offsets
This group of advanced settings refers to the exact point at which a device is switched on or off. The idea is to always have a small differential between the switch ON point and OFF point to avoid device switching on/off too rapidly as this would cause unnecessary wear on the relays and output devices. The switching offsets are also useful to avoid overshoots that invariably occurs when a heater or CO2 is switched off.
We will look at each setting in turn and make suggestions for initial settings which will normally be pre-programmed in when the unit is manufactured. After observing your grow room operating you may decide to change some settings slightly.
Fans ON (+0.2C) OFF (-0.8C)
This setting applies to both fans (if two installed), the second fan coming on after the first has been on for two minutes and temperature is still above the ON point.
Note that reducing the difference between ON and OFF will result in the fans switching ON/OFF more often with increased wear to both the fans and the relays.
AirCon ON (+0.2C) OFF(-0.8C)
This is the same as for the fans.
Note that auto switching from Fans to aircon has a separate rule. Normally, this rule will be to switch over to aircon at say +2C. Once in aircon mode it will stay there until the next time zone or if the temperature falls below the heater ON temp.
Heater ON (-1.5C) OFF (-0.5C)
This gives a buffer of 0.7C between the heater going OFF and the Fan coming on. This may need to be increased a little if it is ever observed that the fan comes on soon after the heater going off.
Humidifier ON (-10%) OFF(-2%)
Dehumidifier ON (+10%) OFF(+2%)
These settings give a difference of 12% RH between one device switching off and the other switching ON. This may need to be increased if you find one switching on soon after the other has switched off
CO2 ON( -200ppm) OFF(-100ppm)
This means that the CO2 will switch on when it falls below 200ppm under the setpoint and will switch off as soon as it exceeds 100ppm below the setpoint. The reason for switching off before the setpoint is reached is that there is always some overshoot with CO2. Depending on your exact setup you may need to alter this to achieve what you desire.
To read , please click the link.