18 May 2017
Cooling systems in buildings currently represent an issue in terms of energy consumption. The electrically driven chillers are used in most cases while cooling loads cause overloading of the electricity distribution system during summertime. This situation is significantly energy consuming in the case of hotels, where domestic hot water (DHW) consumption appears, often simultaneously.
Solar cooling systems (SCS) designed for full or partial coverage of the cooling load can decrease electric consumption peaks in buildings and consequently also consumption of non-renewable primary energy. Even more significant savings can be achieved by using the rejected heat of solar chillers for DHW preheating or for heating of open pools in Mediterranean coastal type hotels so that to maximize the overall EER and COP of the whole installation.
DHW consumption and pool heating load profiles combined with the cooling peak load profiles are significant parameters for optimizations. Furthermore, the penetration ratio of a solar chiller capacity related to the summer cooling peak load value is a decision tool to achieve significant overall energy efficiency.
In this paper, energy performance of SCS with rejection heat recovery in Greek hotel is evaluated using transient simulation program (TRNSYS) and energy savings are calculated in comparison to compression-based cooling system and gas heater. The optimized overall efficiency of a typical Mediterranean hotel situated in the Rhodos Island has been found according simulated scenarios equal to 7.45. This efficiency is announced for a solar cooling penetration ratio of 28 % referred to the summer cooling peak load.