Microclimatic studies in a double-span greenhouse under wind driven and fan ventilated conditions in west coast of India

Abstract

The microclimate in a double-span greenhouse (with screened vents on all four sides and roof) was studied under wind driven and fan ventilated conditions in 2014-2016. The greenhouse air temperature and relative humidity were monitored year round (ranged from 52.3 to 13.5°C and 100 to 18% in wind driven condition as compared to an ambient air temperature and humidity of 38 to 15°C and 99 to 20%, respectively), while air velocities were measured for short periods with full grown tomato crop at various locations of the greenhouse under wind driven and fan ventilated conditions. The air temperature and relative humidity in the fan (2 nos. 25 cfm)ventilated greenhouse with tomato crop (ranged from 34.4 to 25.3°C and 99 to 30%, respectively, as compared to ambient air temperature and relative humidity of 43 to 11°C, and 96 to 20%, respectively). The highly heterogeneous distribution of air velocities inside the structure under wind driven conditions (east span: (-154.26) to 52.04% and west span: (-68.62) to 39.22%) were improved significantly by the installation of fans (east span: 19.02 to 39.90%, west span: (-57.19) to 39.90%).