INFLUENCE OF TWO NEW GREENHOUSE COVERING MATERIALS ON GREENHOUSE MICROCLIMATE AND COOLING LOAD

Aim of this paper was to study the effects of a new polyethylene (PE) film with high reflectance and absorption in near infrared radiation (NIR-PE) and of a new PE film with low transmittance in infrared radiation IR (IR-PE), on greenhouse microclimate and cooling load of a hydroponic tomato crop.
Films were evaluated in the laboratory and experimentally in three similar arched roof greenhouses, two covered with the new covering materials and the third one by a common PE film (C-PE). The greenhouse and outside microclimate parameters along with crop growth and production were recorded.
Laboratory measurements show that in the total radiation band the NIR-PE film has 13% lower transmissivity than the other two films and 57% higher absorptivity than the C-PE film.
Experimental results show that the NIR-PE covering material reduces significantly the solar radiation entering the greenhouse and resulted in a temperature drop up to 2°C than the air temperature of the C-PE covered greenhouse.
The total production per m² was 12.12 kg, 12.00 kg and 10.25 kg under the IR-PE, the NIR-PE and the C-PE covered greenhouses, respectively with no significant differences between the three greenhouses.

International Symposium on Advanced Technologies and Management Towards Sustainable Greenhouse Ecosystems: Greensys2011

E. Kitta, T. Bartzanas, N. Katsoulas

air temperature, relative humidity, energy saving

https://doi.org/10.17660/ActaHortic.2012.952.27