Hot water heating system
Hot water is produced in a central boiler and is usually pumped through the greenhouse. An advantage of the hot water system is that if the boiler fails, the hot water in the hotwater storage andpipes acts as a heat reservoir for a period of time. The systems include water delivery pipes, heat exchangers and circulation pumps for each cycle, electrical valves, railway heating pipes.
Hot air generator
In these types of heaters, the fuel is combusted in a fuel box, and the hot
exhaust is passed through thin-walled metal tubes (heat exchangers). Heat is
transferred to the metal, and the exhaust is removed from the greenhouse through
an exhaust stack. The hot air may be blown directly into the greenhouse or
forced through a polyethylene tube (jet tube) that runs the length of the
greenhouse. These systems may use kerosene, liquid propane, or natural gas as a
fuel source. The system is designed to reach the ΔΤ required by the crop. This
method of circulating the air assures: Uniform temperature throughout the
greenhouse
CO² units
Carbon dioxide (CO2) is an essential component of
photosynthesis (also called carbon assimilation). CO2 increases productivity
through improved plant growth and vigor, expressed in earlier flowering, higher
fruit yields, reduced abscission, and improved stem strength and flower size.
CO2 distribution depends mainly on air movement within the greenhouse. When a
single source of CO2 is used for a large surface area or several connecting
greenhouses, it is recommended to install a distribution system for even
distribution of CO2 , especially when flue gas CO2 or liquid CO2 is used. Air
circulation using horizontal airflow fans or fan-jet systems provide uniform
distribution by moving large volumes of air within the greenhouse when top vents
are closed or exhaust fans are not operational.
Air recirculation fans
Air recirculation are used to move the air in the greenhouse, disperse humidity
and spread heat evenly.
Sulfur evaporators
Sulfur evaporators are an effective method for controlling powdery mildew in the
greenhouse. It is recommended to use sulfur evaporators as a preventative
measure.