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Greenhouse Dehumidification Combined with Heating/Cooling

Two of the most important greenhouse climate conditions impacting yields are humidity and temperature. Growers require tools to control and keep these climate conditions at optimal levels to produce healthy, active plants, which in turn produce high quantity and quality yield. DryGair has designed an innovative greenhouse heating or cooling solution to control both the humidity and the temperature in an energy efficient manner. The solution offers a way to control climate uniformly utilizing significantly simplified infrastructure compared to the alternatives.

One of DryGair’s DG12 or DG6 heating/cooling units provides multiple functions:

DG-12 / DG-6 Heating & Cooling
The heating/cooling option is offered in 2 variants that can gradually increase or decrease temperatures alongside advanced humidity control.

The DryGair Solution Combined with Heating & Cooling - How it Works?


Our growing concept is based on closing the greenhouse, fully spreading the thermal screen (if applicable), and operating the DryGair unit which treats the air and circulate it throughout the crop.

DryGair Combined Heating and Cooling Unit operating in Heating mode<


The DryGair dehumidification combined with heating/coo3ling unit requires an electricity supply, extracted water drainage pipe, and a hot/cold water supply in & out of the unit.
The unit comes with inlet and outlet water pipes which connect to the hot/cold water coil. These pipes must be connected to a water source (chiller/boiler/heat pump).

Hot/Cold Water Coil

DG-12 or DG-6 Heating & Cooling Unit Structure

While operating either modes, the air passes over the heating/cooling coil, depending on the water

temperature supplied to the unit:

Heating Mode
Cooling Mode

Hot water is supplied from the hot water source and passes through the coil. The air that passes across the heated coil is heated before it exits the unit. DryGair recommends supplying water at 85°C (185°F), Water flow rate: 80L/min (21 G/min).


Cold water is supplied from the cold water source and passes through the coil. The air that passes across the cooled coil is cooled before it exits the unit. DryGair recommends supplying water at 7°C (45°F), Water flow rate: 80L/min(21 G/min).

Heating/ Cooling Coil Specifications Per Unit

Water Tempeture Inlet - - Outlet
85o C - - 65o C
185oF - - 150oF
7o C - - 13o C
45oF - - 55oF
Flow Rate
~80L/min (~21G/min)
Pipe Diameter
1 ¼ “ BSP
Resistance to Flow
~100 kPa

The grower determines the desired air temperature set point via a thermostat inside of the unit. The pipes come with a smart valve and bypass function to guarantee the water enters the unit at the appropriate temperature for desired results. Humidity is controlled by setting the desired humidity set point into the unit’s humidistat, or remotely by connecting the unit to a climate control system.


The heating/cooling capacity of the unit depends on:
Temperature of the water inserted into the unit
Water flow rate
Greenhouse climate conditions

HEATING: Heating Mode: The lower the indoor air temperature is, the higher the heating capacity is that the unit can deliver. This mode has a high heating capacity and can be used as a replacement for a heating system. This simple system can replace the heavy infrastructure, maintenance, and costs associated with alternative conventional heating systems and provide comprehensive climate control.

COOLING: The higher the indoor air temperature is, the higher the cooling capacity that the unit can deliver. A portion of the cooling capacity goes to neutralize the heat release as a result of the energy consumed in the operation of the DryGair unit.

The DryGair cooling function offers a solution in conditions where high temperature stress is experienced by plants. The cooling solution creates cooler night time conditions which contrast with hot days, creating daily temperature averages that are better for plant development. Cooling the greenhouse during night time allows the plant’s respiration rate to decrease, and more of the valuable resources it produced during the day are directed to the places that need it such as flowers and fruits. DryGair combined with cooling can supply a reduction in temperature during night time operation, gradually. This is a big advantage over alternatives: wet pad and fan systems which raise humidity levels in order to cool, creating conditions that can lead to plant diseases, or costly HVAC systems which require very high amounts of energy to lower indoor temperatures.


Heating Mode
Cooling Mode

At greenhouse climate conditions of 18°C (64°F), 80% RH, when hot water is supplied at 85°C (185°F) at a flow rate of 80 L/min (21 G/min: • The DG12 Standard unit will produce a heating capacity of ~115 kW (392,000 BTU/h). • The DG6 Small unit will produce a heating capacity of ~90kW (307,000 BTU/h).


At greenhouse climate conditions of 24°C (75°F),80% RH, when cold water is supplied at 7°C (45°F) at a flow rate of 80 L/min (21 G/min): • The DG12 Standard unit will produce a cooling capacity of ~32kW (110,000 BTU/h). • The DG6 Small unit will produce a cooling capacity of ~26 kW (88,700 BTU/h).


The dehumidification and temperature functions are enhanced due to
DryGair’s unique air distribution module.

2 high capacity fans ( 22,000 M3 /h, 13,000 CFM) to take the humid air from between the plants. It than uses a patent protected design which delivers unique 360° air flow distribution to create homogeneous temperatures and humidity levels in different parts of the greenhouse, cultivating uniformity around each plant.


The water in the air is condensed on the surface of the evaporator coils

The DG12 standard unit extracts water at a rate of 45L/h (12 G/h) utilizing 10kW of electricity.*

The DG6 small unit extracts water at a rate of 24 L/h (6 G/h) of water utilizing 6 kW of electricity.*

All of the heat energy harvested from the condensation process and from the operation of the unit is transferred to the expelled dry air, making it warmer

* At designed conditions of 18°C, 80% RH


Lower investment

Lower initial investment on heating/cooling systems

1 Unit With Many Functions

Dehumidification, heating, cooling, and air circulation

Energy Efficiency

stemming from high water extraction per energy consumption (4.5 L/ kWh or 1.2 G/kWh), working within a closed greenhouse, temperature, and air distribution and circulation throughout the greenhouse

Simple, Minimized Infrastructure

In comparison to alternatives such as extensive systems involving heating pipes and ducts. DryGair means lower maintenance costs and clearer working spaces.

Optimal Climate Conditions

The unit delivers the treated air to the tops of plants, where development occurs, in contrast to most alternatives whose point of delivery is at floor level.

Easy Integration

The units can be positioned along the aisles, as part of the rows or on the side of the greenhouse and can be hung. The unit can operate stand-alone or connected to the climate control system. It is available in standard, small, and split units.


The ability to control humidity and temperature in a complicated agricultural environment in an energy efficient way is DryGair’s unique patent. The heating & cooling units offer a growing tool that supports all climate control aspects and air circulation that are needed for commercial cultivation. The specially designed unit optimizes the growing conditions and significantly improves the financial results (Fast ROI). For additional information, refer to the operation manual or contact the DryGair team.


Contact us directly for details and quote for your growing facility

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