ABSTRACT

Predicting greenhouse energy consumption is very important for the development of greenhouse covering materials, the design of greenhouses and the energy conservation in production. More than 70% of the energy consumption in a greenhouse in winter is owing to the heat loss through covering layer. For this reason, an accurate analytical prediction of the heat transfer through covering material is the key point for predicting energy consumption in a greenhouse. Heat transfer through covering material is the synthetical action of conduction, convection and radiation, etc. The amount of the heat loss through covering layer is mainly dependent on the thermal properties of covering material, the type of greenhouse construction and the environment it works in. Heat radiation can pass through covering material to make heat exchange between inner and outer of a greenhouse owing to its transmission character for visible light and long-wave radiation, which is different from ordinary building materials.