The main goal of greenhouse gardening is to provide a controlled environment for the plants you are growing. In warm months and sunny days, this requires a source for cool air intake. There are two primary forms of cooling your greenhouse. Passive ventilation is still the most popular form of cooling as it is the most natural and gentle for your plants. This is achieved through automatic ridge vents and optional side venting. Relying on convection, the hot air will naturally rise out and lower cooler air can be drawn through the lower openings.
For larger greenhouses or hotter climates, a forced ventilation system may be necessary to ensure the greenhouse does not over heat. This will usually include a combination of exhaust fan, motorized intake shutters and thermostat, providing a more controlled environment. When choosing a forced ventilation system, plan on relying on it for most of spring, summer, and fall; during the colder winter months a passive ventilation method through venting offers a less extreme temperature fluctuation.
Diffusing the sun`s light will also minimize heat build up and harmful rays. Many plastic coverings act as a built in shade system. With a glass greenhouse, some form of shading will be required if there is not adequate natural shade available.
Have a circulating fan moving air in your greenhouse at all times. Although the idea is basic, the principle is critical. Plants need fresh air for a healthy root system and a constant flow of air prevents pockets of warm or cool air staying in corners. It will regulate the overall temperatures and increase efficiency in the greenhouse. This will also prevent mold from forming on walls or plant containers as condensation is less likely to settle especially in a structure like ours that is so well sealed for inclement weather.
To create a micro weather system - place your heater on the floor pointing into greenhouse closest to the door. This is where there is the greatest amount of heat loss. Put a circulating fan on bench level pointing up and towards the door. This will create a circular motion of needed air for your plants and increase efficiency in the greenhouse. If you have a larger greenhouse, a few small Caframo circulating fans will be your best friend. Talk to us about your circulation and ventilation needs!