- Issue Time
- Mar 11,2023
VPD is a measure of the difference between the amount of moisture in the air and the maximum amount of moisture that the air can hold at a given temperature.
Plants release water through their leaves by transportation while water takes the nutrients to each part of plant. In this case low humidity environment will stimulate speed of nutrient transportation. So the VPD is widely used by growers to evaluate the environment of growing.
VPD stands for Vapor Pressure Deficit. It is a measure of the difference between the amount of moisture in the air and the maximum amount of moisture that the air can hold at a given temperature. VPD is used to evaluate the water requirements of plants and to optimize the growth and development of crops in greenhouses, indoor gardens, and other controlled environments. Maintaining appropriate VPD levels can help prevent plant stress, mold, and other issues that can negatively affect plant health and yield.
There are many factors that determine the plants transpiration in grow room. The VPD chart of plant grow humidity and temperature will help to learn the best humidity to plant grow.
The total amount of plant in your grow room, and the amount of foliage on each plant need to be considered for transpiration. The local climate (humidity and temperature) will also affect the grow room humidity. The size of your grow room, water remove capacity of dehumidifier, plant quantity should match.
So the designed water remove capacity of your dehumidifier groups should be bigger than grow room calculation in case any different periods of plant transpiration and climate seasons.
The ideal humidity for plant growth varies depending on the stage of growth. During the vegetative stage, the humidity should be between 40% to 70%, while during the flowering stage, it should be between 40% to 50%. High humidity levels can lead to mold and mildew growth, while low humidity levels can cause dehydration and stunted growth. It is important to maintain the appropriate humidity level to ensure healthy growth.
In order to keep 40% to 60%, the refrigerant dehumidifier SDT-150L can be your best Choice for greenhouse.
You need to know your room size such as length x width x height in your grow room firstly. Normally if you would like to use the advanced controlling system, such as Trolmaster to connect with dehumidifier. It will be easier to control your whole grow room humidity, light, CO2 together. And SDT-150L is third-party terminal ready for Trolmaster controller. The suggested area for SDT-150L is 1300~1800 Sqft. You can also let us know your grow room information so that we can suggest most suitable dehumidifiers to save your cost.
The humidistat SDT-24DA is included with SDT series dehumidifiers. It can be used not only for EAST SDT grow dehumidifiers, but also can be used as a third party controller to other modern brand dehumidifiers.
In order to match current modern dehumidifiers & third party controller system perfectly. The SDT Grow Dehumidifier provide 24V DC power for both 24V AC or DC third party controller. While the controller SDT-24DA can be powered by both 24V AC or DC.
Connecting the HS-1 to spare plug as the schematic shows, and insert the plug into the socket of dehumidifier.
Then you can enjoy the performance of controlling by Trolmaster.
*Only for SDT series grow dehumidifiers