Study of coupled energy saving systems sensitivity factor analysis
Résumé
This study was carried out on a real site of a gymnasium situated in the centre of France. The building is equipped with two remarkable energy saving devices running together: a ventilated roof and an air-earth heat exchanger. Experimental and theoretical studies were done on these two energy saving systems and a sensitivity factor analysis was performed. First, each component was modelled in order to (1) determine the component's contribution to the energy savings; and (2) indicate the relative importance of different types of heat transfer which occur in the ventilated roof. Then, several types of fresh air preheating were studied, varying the heating control temperature of the building. The main results show that the economy of fresh air preheating can vary with the system used, and indicate the reasons for the lack of efficiency of some systems. Finally, fresh air introduction into the gymnasium was optimized. The combined influences of ventilation intermittency and climate on the global theoretical consumptions for the building were studied. It was shown that the optimization of air introduction into the gymnasium has no influence on the energy consumption of the building for a rather cold climate. On the other hand, for a warmer climate, significant energy savings can be obtained. In conclusion, this study points out the general interest of simulation for new building designs. However, it can be also used for existing buildings to give significant information about equipment weaknesses and, of course, about improvements to be made.