Control the Humidity & VPD in Your Grow Room for Optimum Plant Growth The GAS Intelligent Humidity Controller takes care of the humidity levels in your grow room for faster growth rates and happier plants. Air temperature and humidity are the two factors that affect something called Vapour Pressure Deficit (VPD), which is literally the "drying" ability of the air. For plants to grow at their max, the humidity needs to be within the right range for the particular temperature of the air (and the growth stage of the plants). Until now there has hasn't been an easy solution to optimise the VPD of a grow-space. The Intelligent Humidity Controller changes all that by switching humidifier(s) on and off automatically to achieve the optimum humidity level for the current temperature. G.A.S. make a version of this Humidity/VPD Controller specifically for their SonicAir Pro Humidifier To read more about the G.A.S. Humidity/VPD Controllers take a look at our blog Here To find out more about VPD take look at our Vapour Pressure Deficit blog here or take a look at our VPD video blog here. How the G.A.S Intelligent Humidity Controller Works The Intelligent humidity / VPD controller uses a 3-in-1 probe to sense the temperature, the humidity and the light level in a grow-space. The unit then controls a G.A.S SonicAir Pro Humidifier to either increase the humidity to a user programmed level, or automatically reduce the VPD to the ideal level for the user-set growth stage and day/night phase. There are 4 basic modes of operation which are as follows: 1) Relative Humidity 24 Hours - In this mode the controller will control the humidifier pro in order to increase the humidity to the level set by the user. 2) Relative Humidity Day / Relative Humidity Night - In this mode the controller allows the user to set separate humidity levels for day and night 3) VPD 24 Hours - In this mode the user sets the stage of growth that the plants are in (Early Veg, Early Flower, or Late Flower). The controller then automatically calculates the humidity level to achieve the ideal VPD for the current temperature and the stage of growth and then controls the humidifier to get the humidity into the ideal range. If you really want you can override the preprogrammed VPD setting for each growth stage and set your own target VPD level. 4) VPD Day / Relative Humidity at Night - During the lights-on period, the unit operates as described in mode 3. However, during the dark-period, it will switch to just controlling the humidity (not the VPD) to a user-set level. The stomata on plants are closed when the lights are off (to prevent unneccessary water loss) because they are not photosynthesising and therefore do not need to transpire. This means that when the lights are off, the VPD is not important. However, high humidity conditions during the lights-off period can encourage mould. It is only important to control the relative humidity during the night, not the VPD. In our opinion, mode 4 is the best. It controls the VPD during the day when it is important, and controls just the relative humidity during the night when that is most important. Please Note: While the G.A.S Humidity Controller is a very clever & useful piece of equipment, it can only increase humidity to the correct levels but it cannot reduce humidity levels to bring them within range. However the use of a separate adjustable dehumidifier alongside this controller and a humidifier pro can bring down humidity levels when they are too high. To see our full Grow Room Humidifiers & Dehumidifiers range, click here
