Prediction of temperature and relative humidity inside the greenhouse in relation to amhient condition

The temperature and relative humidity (RH) inside the naturally ventilated and evaporative cooled greenhouses were recorded at 10 a.m, 1 p.m and 4 p.m for one year for gerbera crop. The ambient temperature, RH, wind velocity and pan evaporation were recorded. The linear regression model was fitted for monthly average of greenhouse temperature and RH for estimating these in relation to the ambient temperature, RH, wind speed and pan evaporation for naturally ventilated and fan and pad greenhouses separately. It was observed that the temperature inside the naturally ventilated greenhouse (NVGH) was directly related to ambient temperature (R²= 0.93). The RH inside the NVGH was also directly related to the ambient RH (R²= 0.96). The effect of ambient RH was negligible on the temperature inside the NVGH. The effect of ambient temperature was also negligible on the RH inside the NVGH. The effect of ambiait wind speed and pan evaporation was also negligible on temperature and RH inside the NVGH. The temperature inside the fan and pad greenhouse (FPGH) was dependent on ambient temperature and pan evaporation (R²= 0.49). The RH inside the FPGH was dependant on ambient temperature and RH (R²= 0.72). The regression models are useful to estimate the temperature and RH inside the naturally ventilated and fan and pad greenhouses based on the ambient condition.