Design and technology for greenhouse cooling in tropical and subtropical regions: A review

Greenhouse technology is a viable option for sustainable crop production in the regions of adverse climatic conditions. High summer temperature is a major setback for successful greenhouse crop production throughout year. The main intent of the paper is to present a comprehensive review on the design and technology for cooling of greenhouse during summer months. Effect of characteristic design parameters on greenhouse microclimate and the applicable cooling technologies have been discussed. A detailed survey of literature revealed that, apart from cooling, studies on greenhouse design, evaluation of new cladding materials for greenhouse covering and natural ventilation with respect to local climate and agronomic condition is necessary to achieve desirable benefits. Analysis of the earlier studies revealed that a naturally ventilated greenhouse with larger ventilation areas (15–30%), provided at the ridge and sides covered with insect-proof nets of 20–40 mesh size with covering material properties of NIR (near infrared radiation) reflection during the day and FIR (far infrared radiation) reflection during night is suitable for greenhouse production throughout year in tropical and subtropical regions. Based on the review, salient areas in need of further research are focused.