Initially we need to discuss the addition of heat to the structure. There are two specific objectives in heating a greenhouse. Temperature at plant level must be uniform. Temperature must be steady. Uniformity of temperature is controlled by the type and layout of the radiating surfaces.
Steady temperature is a function of the controls.
It is possible, therefore, to have a uniform temperature that is not steady as well as a steady temperature that is not uniform. The objective is to have the temperature both steady and uniform. Heat Source One of the first decisions to make is whether to use a centralized heating system or to use a localized heating system. Size is a consideration. Large greenhouses often can support a centralized system while small greenhouses may select a localized system.