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.
The DryGair Solution Combined with Heating & Cooling - How it Works?
THE DRYGAIR SOLUTION
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.
GREENHOUSE HEATING &COOLING - TEMPERATURE CONTROL
The DryGair Dehumidification Combined with Heating/Cooling 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 Heating/ Cooling coil. These pipes must be connected to a water source (chiller/boiler/heat pump).
Heating & Cooling Coil
DG-12 or DG-6 Heating & Cooling Unit Structure
When operating the heating/cooling functions, the air passes over the heating/cooling coil, depending on the water
temperature supplied to the unit:
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
185oF - - 150oF
45oF - - 55oF
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.
Temperature of the water inserted into the unit
Water flow rate
Greenhouse climate conditions
HEATING: The lower the air temperature, the higher the heating capacity.
COOLING: The higher the temperature, the higher the cooling capacity. 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/COOLING CAPACITY EXAMLES:
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 Standard unit will produce a heating capacity of ~105 kW (358,000 BTU/h). • The Small unit will produce a heating capacity of ~84kW (286,600 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 Standard unit will produce a cooling capacity of ~32kW (110,000 BTU/h). • The 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 6kW 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 initial investment on heating/cooling systems
1 Unit With Many Functions
Dehumidification, heating, cooling, and air circulation
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.
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.