Agricultural greenhouse structure - involving both transparent and reflective plastics films to retain and distribute internal heat

摘要

An agricultural greenhouse has multiple ridged panels mounted on a frame inclined at 15 deg. with the south end lower than the north end, the relative slopes of successive ridge faces being such as not to cause mutual shading. The structure also includes at least one internal blind to help conserve internal heat overnight. Pref. the northern faces of the ridges and the enclosure walls have an external layer of UV-stabilised polyethylene film sepd. by a few cm from an internal layer of aluminised polyester film such as 'Claryl' (RTM-Soc. Plastic Omnium). The internal blind, extended horizontally to trap warm air at lower levels, is pref. a film of EVA copolymer at least partly covered with a material to reflect infrared radiation back inwards. A pump system may be used to redirect warm air beneath the path of the cover to lower levels. The ridges may include vents which can be opened in summer. Typically the enclosures are inclined at angles of 60-80 deg. to the horizontal. The south faces of each ridge are inclined at 50 deg; The angle of the northern faces depends upon the local solar angle at the winter solstice.