Greenhouse Water Management Greenhouse Heating Systems

Crop Cooling & Humidity Control

Specialty crop growers and researchers are turning to chilled water cooling systems in greenhouses and warehouses because they offer precise cooling and control for cannabis crops.  The ultimate goal is to tightly control the environment.

Hydronics is the use of water as the heat-transfer medium in heating and cooling systems.  A hydronic system may include both a chilled and heated water loop to provide for both heating and air conditioning.  Chillers and cooling towers may be used separately or together to provide water cooling, while boilers heat the water.



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Chilled Water for Humidity Control

Chilled water cooling is a hydronic process by which chilled water is circulated through a loop piping system. Circulator pumps force the water through a heat exchanger, where a fan draws warm air out and cools it as it passes over cold coils.  A system may be broken up into individual temperature zones using either multiple circulator pumps or a single pump and electrically operated zone valves.

Like a radiant heating system, chilled water cooling is controlled and regulated by the environmental controls, allowing growers to precisely control the temperature of the plants and the greenhouse humidity and other climate factors.  Direct digital controls not only provide precise environmental control, but also allow for energy and cost savings. 


Less Humidity than Evaporative Cooling

Most commercial greenhouses use evaporative cooling, which can cool air to about 10 to 20 degrees below the outside temperature.  Evaporative cooling systems lower air temperature using mists, sprays, or wetted pads.  Introducing water into ventilation air increases relative humidity while lowering air temperature. 

The typical evaporative pad cooling system draws outside air into the building through wet vertical pads.  As air flows past the moist pad surfaces, some of the moisture evaporates into the air stream.  Heat is withdrawn from the air during this process and the air leaves the pad at a lower temperature with higher moisture content.

Standard systems dehumidify to the point of 10 to 20% relative humidity when cooling for long periods of time, but this is too low for proper growth and production.  The Delta T Solutions system controls relative humidity better because it provides both cooling and humidity control, without dehumidifying to the extreme.

The process Delta T Solutions offers also cools the air to a temperature at or around dew point to avoid condensation of the air and excessive humidity. This gives growers the assurance that their crops can grow in a healthy, high yield environment.


Customized Cooling Solutions for Growing

Chilled water cooling provides precise control and are typically developed as a custom solution for each operation.  Consider these factors when selecting chilled water cooling systems:

  • Installed cost
  • Energy consumption
  • Space requirements
  • Freeze prevention
  • Precision
  • Growing area height, size and shape
  • System cooling and heating capacity
  • Centralized maintenance
  • Stability of control

To learn how your operation can benefit from chilled water cooling, contact us at 800-552-5058 or email


    Delta T Solutions Greenhouse Heating Creating Custom Horticultural Heating & Cooling Solutions For Over 30 Years
Delta T Solutions • 27711 Diaz Rd, Suite B • Temecula, CA 92590
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