Angelotti A., Pagliano L., Solaini G.;
June 2004
EuroSun2004, p. 678-686
During the last years in Italy and in southern European countries the demand for summer comfort has been rapidly growing. The increasing popularity of air-conditioning is producing a significant rise of the electricity consumption, causing serious security of supply and environmental concerns. In this context there is a great interest in the techniques that can be applied to provide thermal comfort with a low energy consumption. Among them indirect ground cooling represents a promising option. A few meters under the surface the earth temperature is stable all over the year and significantly lower than the ambient air temperature in summer. By using proper earth-to-fluid heat exchangers indirect coupling between the building and the ground is achieved and the building thermal loads can be transferred to the ground. Most experimental and theoretical studies on ground cooling systems focus on air as the thermovector fluid [1-6]. Anyhow the use of air can lead to some sanitary problems due to the presence of stagnant water, either caused by humidity condensation or by infiltration from the surrounding medium. On the other side earth-to-water heat exchangers are commonly used in conjunction with ground source heat pumps, resulting in more complex and energy intensive systems. A test ground cooling system built in Milano, connecting earth-to-water heat exchangers to radiant panels in the building without making use of a heat pump, has been proposed and studied by the authors [7-9]. In this paper the results of a monitoring campaign carried out using the experimental set up are reported and discussed. A dynamic simulation model, developed within the TRNSYS environment, is used to simulate the system and the building. Two performance indicators, one for comfort conditions and one for energy efficiency, are introduced. Through dynamic simulations the influence of the main parameters on the system performance is investigated, obtaining some operating and design guidelines.