SOLAR-RADIATION TRANSMITTANCE OF A DOUBLE-WALLED ACRYLIC PELLET-INSULATED GREENHOUSE

Experiments were conducted to study the major characteristics of solar radiation transmittance of a prototype greenhouse glazed with double- walled acrylic panels and a polystyrene-pellet insulation system. A gr oup of radiometers was used to measure radiation transmittance for bot h clear and overcast days and for different percentages of pellet shad ing. Diffuse radiation transmittance was found to be independent of so lar position. For clear days, solar radiation transmittance was the hi ghest at noon and during the diffuse periods of sunrise and sunset. Li near relationships between the solar radiation transmittance and the p ercentage of pellet shading were established.