The Effectiveness of Using Two Sustainable Night Heating Modes on Greenhouse Cultivation

The main purpose of this paper is to study the efficiency of the deployment in Tunisia of the Ground Source Heat Pump (GSHP) system and of a solar air heater with latent storage (SAHLS) for heating mode application. A pilot GSHP system using conic ground heat exchanger and a SAHLS were installed and experimented in the Research and Technology Center of Energy (CRTEn), Borj Cédria, northern Tunisia. The status of geothermal and the solar air collector energies and their utilization are pointed out, the evaluation of both systems is examined for air heating. Their effect in the growth rate and yield of tomato are also studied. The main results show that the SAHLS gives the appropriate microclimate for plants under greenhouse in comparison with GSHP: high night temperature and low relative humidity. This leads to earliness of 2 weeks and a good quality and quantity of fruits represented by high relative growth rate, high phenolic compounds and a high quantity of marketable fruits.