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. Cost is a consideration. Centralized systems are more expensive to install than are laocalized ones. Type of fuel may be a considration. Coal and low grade oil can not easily be burned in localized systems.