Articles
INVENTORY OF MORE SIGNIFICANT PARAMETERS WHICH CAN BE USEFUL TO CHARACTERIZE ENERGY REQUIREMENTS FOR HEATING
QH = k’ AS . (tGH – t
) – QS (W)
QH is the energy requirement of the greenhouse, k’ is the over all heat consumption coefficient, AS is the surface area of the greenhouse, tGH is the inside air temperature, t
the outside temperature and QS is the amount of solar radiation, which comes into the greenhouse and is converted to sensible heat.
The energy requirement of the greenhouse can be influenced by changing the parameters in the above equation.
The surface area AS of the greenhouse can be decreased by building multi-span greenhouses instead of single span greenhouses with the same total ground area.
For characterizing a greenhouse, the relation between surface area and ground area AS/AG is a more significant parameter.
A small single span greenhouse has a factor of AS/AG = 1. 8 to 2.0 and a large multispan greenhouse has a factor of AS/AG = 1.2 to 1.5.
