Solar radiation; Greenhouse; Solar fraction; Thermal heating
A considerable portion of the solar radiation falling on transparent north wall/roof inside an east–west-oriented greenhouse is lost due to low-altitude angle of sun during winter months. Replacing the transparent north wall with a reflecting surface can increase solar radiation on the floor of the greenhouse. Effect of vertical and inclined reflecting north wall on distribution of solar radiation on the floor of greenhouse has been studied for five different locations in India. These locations are Chennai (13°N), Kolkotta (22.53°N), Jodhpur (26.30°N), Delhi (28.58°N) and Srinagar (34.08°N). Evenspan greenhouse (6 m×4 m×3 m) has been considered for the present study. The proposed model can also be used to determine the distribution of solar radiation for any other place and shape of the greenhouse.