Energy conservation in commercial greenhouses operated in cold climates

The primary objective of this paper is to show the distribution of heat losses in prairie commercial greenhouses of various constructions and to suggest and test methods of energy saving. Seventy five percent of the total heat loss is through the roof of a glass greenhouse. This can be significantly reduced by adding an extra layer of polyethylene preferably in the area where lower lightlevels can be tolerated. The average infiltration losses were found to be about 10% of total heat losses, which is small compared with the roof heat loss in the commercial greenhouses, therefore extensive sealing around the greenhouses is not worthwhile.