Formulation and validation of a mathematical model for a naturally ventilated greenhouse with shading nets in warm and humid climate of India

A thermal model is developed to investigate the suitability of a simple, inexpensive and naturally ventilated greenhouse with shading nets in warm and humid climatic condition for off-season cultivation of vegetables like okra, cucumber, etc. during winter. These vegetables are generally grown during summer and the rainy season. The study was conducted from November 2011 to February 2012 in OUAT, Bhubaneswar, and Odisha where warm and humid climate usually prevails. Air temperatures inside the greenhouse with shading net were only 1–2°C higher during peak sunny hours and considerably 3–5°C more during night hours compared with ambient air temperatures. Lowering of air temperature during peak sunny hours and increasing during the night due to use of shading nets would become favourable for growing off-season vegetables in naturally ventilated greenhouse. Predicted values of air and plant temperatures were found to be in close agreement with experimental values.