What is Mechanical Greenhouse Ventilation?
Mechanical greenhouse ventilation moves air along the length of the greenhouse. An exhaust fan at one end forces air out creating a vacuum that draws air in through intake shutters on the other end of the greenhouse. Louvers are motorized, and along with fans, are connected to a thermostat and accompanying sensor to first open the louvers and then fire up the exhaust fan(s). It is very important for thermostats and sensors to be properly placed and exhaust fans to be properly sized or they will not be able to ventilate the greenhouse efficiently. In some very hot climates, mechanical ventilation may need to be paired with other cooling equipment like evaporative cooling pads.
Mechanical (Active) Greenhouse Ventilation
Active greenhouse ventilation uses mechanical features to create airflow and circulation. These systems can be automated using control boxes and computer monitoring to provide a high level of environmental control. Active ventilation systems do not rely on external conditions like wind or outside air temperature to cool the greenhouse and have the added advantage of providing a closed environment that reduces pest exposure.
Some active ventilation systems are simple systems using just exhaust fans and shutters. Greenhouse ventilation can get much more intricate by utilizing circulatory fans, heaters, heat exchangers, forced air tubes, and other technologies. Many options are available to design highly controlled greenhouse environments.
Mechanical Ventilation Features
- Exhaust fans and shutters
- Circulatory fans/horizontal airflow systems
- Heat exchanger to warm air that is pulled in from outside before mixing with air in the greenhouse
- Dehumidification, Heating & Cooling units
- Allow for a high degree of environmental control
- Ventilator (two, one to pull air into the heat exchanger and one to push it into the greenhouse) and air hoses or tubes to disperse air
- Can be run in 4 stages to ventilate with heat recovery, without recovery, with recovery and recirculation, and to only recirculate air
Mechanical Greenhouse Ventilation Equipment
When it comes to natural vs mechanical ventilation, mechanical ventilation is going to be more costly than natural ventilation. However, in certain climates and with particular crops, mechanical ventilation might be a must. Here are some of the common types of mechanical greenhouse ventilation equipment:
J&D Aluminum Power Intake Shutter
- Available in 12”, 16”, 18”, 20”, 24”, 30”, 36”, 40”, 42”, 48”, 54”, 60” and 75″
- High-efficiency shutter with tie bar to eliminate shutter flapping
- Nylon bearings and solid shafts for smooth performance
- Heavy-duty aluminum extrusion frame and strong welded corners, all at an affordable cost
- These aluminum exhaust shutters are designed to be used with J&D exhaust fans
- Shutter Motor Kit for 12"-60" J&D Shutters
J&D Manufacturing ES Shutter Fan
- Durable agriculture grade exhaust fan perfect for greenhouses, warehouses, and more
- Available without a cord, or pre-wired with a cord and plug for “No Electrician Required” installation
- Fans ship fully assembled out of the box
Hortitech Direct offers many options for greenhouse kits with both automated and manual ventilation!