There are two ways to ventilate greenhouses: manual and automatic. Automatic ventilation of the greenhouse can be hydraulic, electric, bimetallic or in the form of an automatic window.
Benefits of automatic greenhouse ventilation
Many owners of greenhouses are not constantly at their sites, so they can not organize manual ventilation. In this case, it is more convenient to mount automatic ventilation of the greenhouse.
The electrical ventilation system is easy to install and maintain: only a thermal relay and fan are required. The relay sets the temperature at which the fan should start. Such fans can be supplied as many as you want throughout the entire structure of the greenhouse. There are relays that regulate the intensity of the air stream. The disadvantage of this greenhouse ventilation system is that the windows open with complex and not cheap mechanisms. In addition, a constant source of electricity is needed. The easiest way out of the situation is solar panels.
Hydraulic ventilation system
Hydraulic ventilation in the greenhouse is widely used. Simple design, working for a long time without breakdowns are levers that open the window.
Water in the system is heated, its volume increases, the lever rises and opens the transom. As soon as the water cools, the window closes. A water tank is installed in the greenhouse, acting as a “thermometer”. On the street, another tank is installed, which is connected by pipes to the internal one according to the principle of communicating tanks. Due to the presence of an external tank, the pressure in the system rises gradually, the window opens slowly.
The disadvantage of the system is too slow heating and cooling water, which complicates the calculation of greenhouse ventilation. The air temperature in the street will drop much faster than it "reaches" the mechanism. And tender plants can die.
Bimetal ventilation
The operation of this greenhouse ventilation system is based on the expansion of the metal when heated. The mechanism is made of two different metals with different characteristics. Therefore, when the temperature rises, one metal plate bends and opens a window. The second closes during cooling. This is a very inexpensive system that is easy to install. But its drawback is that the plate power may not be enough if the window area is large. And to make an accurate calculation of the ventilation of a greenhouse at certain temperatures can be difficult.
