Novice gardeners believe that an installed polycarbonate greenhouse is already a guarantee of a high yield. However, this is only a structure, and for proper development, plants need a favorable microclimate inside. Ventilation in the greenhouse, provided by manual and automatic mechanisms, helps to create and maintain it.
Manual ventilation: windows and doors
The simplest way to organize air movement in your greenhouse is to use doors and windows. Open them when it gets hot and close them when the temperature drops or it gets too dry inside.
Polycarbonate creates a protective dome around plants, but moisture accumulates along with heat. It is important to place windows at different heights for air exchange. Thus, the accumulated hot air with carbon dioxide exits through the upper windows, and cool air enters through the lower openings.
The method is economical, but not flawless. The summer resident’s hand will constantly reach out to the windows. In this case, you will not be able to correctly determine “by eye” the need for ventilation. To do this, you will need at least a thermometer in the greenhouse, and ideally a hygrometer. Therefore, gardeners are trying to automate this process and free up time for more interesting activities in the garden.
Automatic ventilation mechanisms for greenhouses
Ventilation in a greenhouse ceases to be a big problem when using automatic systems.
Oil automatic window opener
The most common mechanism is an oil piston. It should be installed on the window and transom. The piston Automatic Window Opener does not require any external power source. The operating principle is simple and reliable. The oil in the cylinders heats up, expands and pushes out the piston, which moves the lever and raises the window. When the oil cools, everything moves in the opposite direction.
Such a mechanism must be installed on each window for ventilation.
Hydraulic opener
An alternative to an oil mechanism is a hydraulic one. It consists of levers, a transom, a hydraulic hose and two containers with liquid. One container is located inside the greenhouse and performs the function of a thermometer. The second is installed outdoors for compensation. When the internal temperature rises, the levers slowly raise the transom, and when it decreases, they lower it. The main disadvantage of the system is the speed of response to temperature changes. The transom closes slowly, and a sharp cold snap can cause the plants to freeze.
Bimetal opener
Another autonomous way to ventilate a greenhouse is a bimetallic system. Like the previous two, it operates on the principle of expansion. In this case, under the influence of temperature, a metal plate increases and straightens, which opens the window. As the plate cools, it returns to its original shape.
Electric method
Thermal relay with fan is a necessary mechanism for exhaust ventilation. The fan starts when the relay is activated at a certain temperature. The method is effective, but requires a connection to electricity, so it is not always available. In our store you can order a Solar-powered Thermostatic Fan. It operates autonomously from sunlight and does not require external energy sources.
Temperature and humidity are important factors in crop growth. Therefore, knowledge of how to properly ventilate your greenhouse is simply necessary to obtain the desired harvest. Which ventilation method to choose depends mainly on the area of the greenhouse and your grown plants.