Studies on thermal performances of a new greenhouse cladding material

Cladding material is one of the most important parts of a greenhouse. Therm al performances of a new bi-oriented corrugated rigid sheet of polyvinyl ch loride (PVC) were studied by spectral measurements and dynamic simulations. Analysis of the data based on the experimental spectral values led to a fi rst improvement by a 5 % relative increase in the PAR transmittance. Furthe r studies on thermal performances of the new PVC sheet with four other simi lar materials were performed by a dynamic energy balance model in both pass ive and active greenhouses over six months. The simulation results showed t hat an 'ideal' PVC sheet with low emittance In thermal infrared radiation w ould reduce the annual heat load by 21 %. ((C) Inra/Elsevier, Paris.).