Development and Application of a Mathematical Simulation Model to Evaluate Environmental Performance of Greenhouses Using Physical and Climatic Indicators

Abstract

This study was conducted to determine and apply a mathematical model to simulate the environmental and climatic parameters to evaluate the performance of different greenhouses in three areas within the Khartoum North – Sudan (Date Palm Technology Company., Abu Halima Center and Khartoum University). The assessment method depends on development of a computer simulation model to generate from house physical characteristics and climate data ten environmental performance evaluation indicators (Relative moisture efficiency; Cooling effectiveness, Moisture saturation efficiency; Water consumption rate; House overall efficiency; House ventilation rate, Optimum internal temperature and internal relative humidity).The result of application of the evaluation model for nine greenhouses in three different locations in Khartoum North reveals that there is no significant differences (P = 0.05) in evaluation indicators between the three studied areas. The study concluded that additional work is needed to upgrade the mode of running greenhouse crop cultivation system with regards to: using sustainable and energy efficient cooling and ventilation technologies, adopting new techniques to conserve water and its efficient utilization, introducing properly adapted materials for high temperatures and strong solar radiation, and accessibility of technologies such as automation systems. In the current system moisture use efficiency in particular found to be lower than expected and measures to improvement are critically needed. With respect to the system efficiency and utility of fan and pad greenhouse the effectiveness of cooling system is function of internal environmental parameter (temperature and relative humidity with negative relation). The evaluation model shows that cooling efficiency tends to go up in the areas with low relative humidity.