Beneficial use of two packed beds of latent storage energy for the heating of a hydroponic greenhouse

Abstract

The intensive energy requirements, the mismatch between the energy supply and demand and the nocturnal temperature drops are all crucial issues in the greenhouses solar heating. This paper seeks to evaluate the effect of a solar air heater with thermal latent storage on the greenhouse microclimate by pursuing the evolution of the internal climate before and after the heating. In this context, an experimental hydroponic greenhouse (HYDGR) and a solar air heater (SAHLSE) were realized in the Thermal Processes Laboratory in the Research and Technology Center of Energy of Borj Cédria in Tunisia. The solar heating with thermal energy storage enhanced the microclimate of the greenhouse and the temperature didn’t drop less than 32 and 15°C respectively the day and at night. The realized solar collector with thermal latent storage offered higher temperature even when the sun is unavailable and increased the internal temperature by more than 5°C. The studied solar system realized good improvement in the hydroponic greenhouse and appeared to be a beneficial alternative for ensuring optimal microclimate.