Natural ventilation offers a certain amount of cooling, but is generally insufficient in South Africa.
To provide an optimal climate in a greenhouse, you need to consider two key aspects: ventilation and ambient air temperature control.
VENTILATION
A number of ventilation systems are available for plastic greenhouses. One of these is a gearbox-and-cable system that pulls the sheeting away to form a ‘chimney’ effect through which warm air can escape.
Another is a motor-driven and roll-up lateral vent system, where the sides of the greenhouse are opened to regulate air flow. There are several variations of this system.
COOLING
Because a tunnel heats up very quickly in warm weather, it is important to cool the interior efficiently to a temperature that benefits plant growth. One of the most effective ways to do this is the pad-and-fan system.
Esta historia es de la edición July 5, 2019 de Farmer's Weekly.
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Esta historia es de la edición July 5, 2019 de Farmer's Weekly.
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