Modeling and Design a Special Type of Passive Solar Greenhouse in Cold Climate by TRNSYS

Abstract

To improve the thermal performance, storage and saving heat solar energy of conventional greenhouse, a passive solar greenhouse was built which its north wall was made of soil. The bottom part of the north, south, west and east walls were sloping and constructed below ground surface. The indoor air temperature was measured during January and February. To optimize the size of greenhouse in cold climate condition a TRNSYS model was created and validated using experimental data. According to the results obtained, Total Incident Solar Radiation (TISR) in the north wall was 484 MJ during January and February and there was the possibility of cultivation in it. More specifically, the variation of TISR during 60 days varied from 190 to 3811 kJ h-1 m-2. The indoor air temperature of the greenhouse varied from -4.3 to 42.4 °C while the outdoor temperature fluctuated between -13.8 to 10.6 °C. In addition, the differential temperature between modeled and measured data at climate conditions of snowy, rainy, cloudy and sunny days were 2.3, 0.2, 0.2, and 2.6 °C during daytime and -1.8, -2, 0.3 and 1 °C at nighttime, respectively. The obtained coefficient of determination (R2) was 95.95% for measured and modeled data.

Keywords

• passive solar greenhouse
• renewable energy
• trnsys
• solar radiation