Feasibility study of solar desiccant cooling for an institutional building in subtropical Queensland, Australia

Institutional buildings contain different functional spaces which require different types of heating and ventilating air conditioning HVAC. In order to provide a suitable work environment for the occupants of an institutional building, the buildings (HVAC) system must provide a thermal comfort level and a healthy living environment. However the extensive use of conventional cooling systems in institutional building consider as the biggest energy consumer. Building designer’s main task is to maintain the optimal indoor comfort condition with minimal energy consumption and minimal environmental negative impact. Now a day there is a big interest in non conventional HVAC system especially in solar thermal cooling technologies. The most common types of solar cooling technologies are: solar absorption cooling system and solar desiccant cooling system. The use of a solar desiccant cooling system to reduce moisture from the air and to improve indoor air quality is found to be economical, environmental friendly and readily achievable in the tropics. In this study a feasibility study of solar desiccant cooling system in an institutional building under Queensland subtropical climate namely the city of Rockhampton will be presented using different types of solar collectors. The study will focus on system technical performance using TRNSYS 16 under a typical meteorological year TMY. It first introduces the issue of Indoor air quality, thermal comfort standards, humidity, air moisture, mould growth and then the technical performance of thermally activated desiccant cooling technology. Results showed that during cooling season 1.2 Coefficients of performance COP can be achieved with 60% of annual solar fraction if a 20 m2 of evacuated tube collectors area and 1.5 m3 of solar hot water storage volume installed section.