Solar-ice systems for multi-family buildings: hydraulics and weather data analysis

SPF, Institut für Solartechnik, HSR, Hochschule für Technik, CH-8640, Rapperswil, Switzerland

^* e-mail: Dani.Carbonell@spf.ch

Abstract

Dynamic simulations using the TRNSYS environment were used to assess the potentials of solar-ice systems for multi-family buildings in Switzerland. The goals of this paper were: i) to analyze and quantify the effects of different hydraulics in the primary loop (solar collectors, ice storage and heat pump), ii) to determine the energetic performance of solar-ice systems for multi-family buildings and iii) to assess the influence of the chosen weather data on the system performance. Simulations were carried out for a range of collector areas of 1.5 m²/MWh to 2.5 m²/MWh and for ice storage volumes of 0.4 m³/MWh to 0.6 m³/MWh being MWh the total yearly heat demand.

An averaged increase of the ΔSPF of 26% was obtained by using direct solar heat in the warm storage. Adding the possibility to use solar heat for heat pump evaporator, increased the SPF_SHP+ by 31 %. Simulations of eight cities in Switzerland using cold, warm and normal weather data sets from SIA were carried out. Results for Davos and Locarno achieved the best results with averaged SPF_SHP+ of 7.4 and 6.3 respectively. Simulations for the rest of the cities achieved averaged SPF_SHP+ in the range of 3.8 to 4.5. The use a cold weather data respect to the normal one defined by the SIA standard led to an average decrease of the SPF_SHP+ of 25 %. The use of a warm weather data led to an increase of the SPF_SHP+ of 5 %.