A properly sized and installed ventilation system is an absolute
necessity. Greenhouse ventilation systems are composed of several basic
components. You should have an exhaust fan, intake shutters and may have
a thermostat.
The purpose of the greenhouse ventilation system is to keep a good air flow from the front of the greenhouse to the back of the greenhouse. This assists in regulating air temperature. It also moves the air in your greenhouse which helps to make healthier plants.
The proper sizing of a ventilation system is based on cubic foot per minute of air flow. Most manufacturers have done the math for you and have recommended size of system per greenhouse charts.
The proper way to install a ventilation package is to put the exhaust fan up high in the back wall of the greenhouse. The intake shutters should be down low on the opposite wall. If you are using motorized intake shutters and an exhaust fan you should have them wired to a thermostat so that they come on at the same time. If you do this, you can set the temperature at the exact degree that you want the system to come on. It will continue to run until the temperature has dropped below this point. It will come on again when the temperature exceeds the setting. This is just the simplest way to do it.
Some people may not have electricity available at the greenhouse location. There are some solar powered exhaust fans available. I do not have any firsthand experience with these and cannot really speak to the efficiency of them. Also, there are non-motorized intake shutters available. These will simply open mechanically if there is enough of an air flow to permit it.
Another way to get some passive ventilation is through the use of side vents in conjunction with your roof vents. Almost all of the greenhouse kits available on the market have roof vents in them. The side vents would simply be placed at the bottom of the greenhouse directly below the roof vents to allow for maximum air flow.
Of course I have talked to many people through the years who have built and designed their own greenhouses using recycled windows. Just open the windows and you have natural ventilation.
No matter how you do it, a good, reliable ventilation system is a must for a greenhouse. Don't overlook this important aspect for a properly controlled temperature and healthy, happy plants.
The purpose of the greenhouse ventilation system is to keep a good air flow from the front of the greenhouse to the back of the greenhouse. This assists in regulating air temperature. It also moves the air in your greenhouse which helps to make healthier plants.
The proper sizing of a ventilation system is based on cubic foot per minute of air flow. Most manufacturers have done the math for you and have recommended size of system per greenhouse charts.
The proper way to install a ventilation package is to put the exhaust fan up high in the back wall of the greenhouse. The intake shutters should be down low on the opposite wall. If you are using motorized intake shutters and an exhaust fan you should have them wired to a thermostat so that they come on at the same time. If you do this, you can set the temperature at the exact degree that you want the system to come on. It will continue to run until the temperature has dropped below this point. It will come on again when the temperature exceeds the setting. This is just the simplest way to do it.
Some people may not have electricity available at the greenhouse location. There are some solar powered exhaust fans available. I do not have any firsthand experience with these and cannot really speak to the efficiency of them. Also, there are non-motorized intake shutters available. These will simply open mechanically if there is enough of an air flow to permit it.
Another way to get some passive ventilation is through the use of side vents in conjunction with your roof vents. Almost all of the greenhouse kits available on the market have roof vents in them. The side vents would simply be placed at the bottom of the greenhouse directly below the roof vents to allow for maximum air flow.
Of course I have talked to many people through the years who have built and designed their own greenhouses using recycled windows. Just open the windows and you have natural ventilation.
No matter how you do it, a good, reliable ventilation system is a must for a greenhouse. Don't overlook this important aspect for a properly controlled temperature and healthy, happy plants.
