ENERGY SAVING IN FILM GREENHOUSES

The experimental greenhouse was covered with Polycarbonat sheets in sidewalls and gables and with EVA-film at the roof.

Comparing single film, single film with thermal screen, double inflated film and double inflated film with thermal screen the last one had the greatest energy saving rate of 51 % compared with that of single film. Very intersting is the comparism of single film with thermal screen and double EVA-inflated with energy saving rates of 40 % and 30 % in comparism with single film.

Theoretical calculations have been made for obtaining the actual heat consumption of film greenhouses covered without materials other than film.

In order to answer the question of reducing light trans-missivity by adding layers of film or installing a thermal screen measurements has been done. There were no significant differences between the lighttransmissivity of the energy saving systems.

The measurements and calculations have shown that film greenhouses can save energy for heating in winter.

The decision for one of the energy saving systems must be made by consideration the specific economic problems of the grower.

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