Projections of Greenhouse Heating and Ventilation Requirements in the New Valley Under Climate Change Scenarios

Egyptian greenhouse megaproject is expanding all over the country in the recent years. Vegetable optimum growth under greenhouses requires temperature range from 15-32 °C. This study was conducted in Kharga Oasis, the New Valley Governorate, Egypt, in order to investigate the heat requirements and number of mechanical ventilation hours needed for vegetable production under greenhouses during the reference year of 2023-2024, compared to historical period of 1995-2014, and under climate change projections. Four future scenarios were used: SSP1-2.6, SSP2-4.5, SSP3-7.0 and SSP5-8.5) according to the IPCC sixth Assessment Report, with four projection intervals: 2020-2039, 2040-2059, 2060-2079, and 2080-2099. Hourly data was used for the estimation of heat requirements (kwh) when temperatures were lower than 15°C, in a greenhouse of 8.5m width, and 40m length and for the number of hours needed for ventilation if temperatures exceed 28, 30, 23 and 35 °C. The results indicated that total heating requirements decreased gradually from 755.1 kCal (≈0.88 kWh) for the actual estimated (2023-2024) down to 66.1 (≈0.07 kWh) kCal by the years 2080-2099 under SSP5-8.5 scenario. Seasonally, winter months required heating, while the rest of the year minimum temperatures were above 15°C set point. Ventilation hours increased to reach 3564 hours/year under the SSP5-8.5 scenario for the projected time intervals 2080-2099. These results indicate the need for vital attention in constructing new greenhouses, and to find the best cultivation dates for coping with climate change temperature rise till the end of the century.