In some regions, artificial heating is necessary to ensure optimal growing conditions. The following factors must be considered when weighing this option:
- The heating system must be suited to the energy sources available in the area.
- The heat must be dispersed uniformly throughout the entire greenhouse, according to specific crop requirements.
- The minimum average temperature prevalent in the region.
- Expected heat loss from the greenhouse and covering.
- Temperature differences between the interior and exterior of the greenhouse.
Heating via hot water: Steel pipes
Heating via hot air: Polyethylene sleeves
Hot water system: Heat is radiated directly onto the plants from the heating pipes. The hot water is pumped through the greenhouse via insulated pipes, with the heat exchanges maintaining a controlled, uniform temperature throughout the greenhouse. The heaters are powered by diesel fuel, hot water, diesel oil or gas, and all the units are controlled by a central computer system.
Hot Air System: Cold air passes over a burning coil as it is sucked into the greenhouse cavity. The heated air is then released into the greenhouse through sleeves. The air circulation process is executed by means of a centrifugal blower, operated by an electric motor.