All growers must contend with high relative humidity (RH) in their greenhouses. This has motivated DryGair and the Israeli Agricultural Research Center to seek a solution to this issue.
The concept was developed by an engineer, Avraham Arbel, of the Agricultural Engineering Institute at the Israeli Agricultural Research Center (Volcani Center) in Beit Dagan.
It provides advanced solutions to overcome the high RH issue. High humidity inside greenhouses often triggers fungus and bacteria-based plant diseases, which can spread rapidly and damage yields.
The DryGair concept treats the indoor air while working in a closed greenhouse, and the isolation of the greenhouse from the outside environment helps maximize energy use and climate control effectiveness.
The patented solution proposed by DryGair helps growers control the RH and temperature either together or separately, and enjoy the welcome benefit of substantial energy savings. The unique air distribution model provides homogenous climate conditions throughout the facilities that help the grower control and improve yields.
How does it work?
The system draws in air from the greenhouse, condenses the moisture out of it and then releases the dry air through openings at the top of the machine. The condensed water is recycled as distilled water and may be used for irrigation.
The basic unit can draw 22,000 cubic meters of air per hour, from which it condenses about 45 liters of water per hour at a temperature of 18oC and an RH of 80%.
DryGair conserves energy by operating within a closed greenhouse: the indoor energy remains inside, as opposed to ventilation systems which lose heat to the outdoor environment. Additionally, all of the energy invested in the system and the energy released during the condensation process is returned to the greenhouse in the form of heat, thus ensuring significant energy savings.The greenhouse climate, which includes air temperature and RH, is thus able to be under constantly improved control.
DryGair systems operate in a multitude of crops, providing climate control to vegetable, herb, flower, medical cannabis, and organic growers around the world. As mentioned, the basic DryGair system produces 45 liters of water per hour and operates at temperatures of 10 to 25 degrees. In addition to the basic unit, there are units built for working in different climate zones such as tropical regions. The systems are easily integrated into growing facilities, with units built to fit the diverse conditions found in various greenhouses including greenhouses with no aisles or greenhouses with movable tables.
The DryGair solution enables the grower to circulate the indoor air, while creating uniform, controlled climate conditions in the greenhouse, utilizing diverse operating modes:
• Dehumidification only
• Dehumidification and heating
• Dehumidification and cooling
• Heating only and / or cooling only
• Air circulation
DryGair systems have been installed in greenhouses, both in Israel and globally, for diverse crops in differing climate conditions. The solution is patented.
“Our objective is to help growers to get better control in the growing climate conditions while improving the efficiency and increasing grower profit. Growers using DryGair can choose if they want to treat humidity and temperature separately or jointly”. At present this appears self-evident, although this was not always so. Even today, growers in many countries still link dehumidification to temperature control, leading to compromises in crop quality. DryGair has successfully risen to this challenge.