Hybrid cooling systems: A review and an optimized selection scheme

The hybrid cooling system has proved to be an energy saving technology for building air conditioning. Numerous systems combining different cooling processes or cooling machines have been proposed and investigated in the literature. A properly selected hybrid cooling system offers a great reduction in energy consumption and a coefficient of performance improvement varying according to different climates and system designs. This paper provides a detailed review of existing hybrid cooling systems with their corresponding individual cooling machines. A brief state of the art of the most common individual cooling systems in hybrid cooling for building use is firstly presented. Then, the hybrid cooling systems are classified into five main categories according to the combination of cooling processes or machines: Vapor compression based cooling, absorption based cooling, adsorption based cooling, desiccant-evaporative and multi-evaporator cooling. In each category, the studied configurations and the benefits of each hybridization method are presented. It is found that each hybrid system combines the advantages of the different cooling processes used. However, a hybrid system could have a negative repercussion if it does not match the climatic zone where it will be used. Consequently, a selection scheme to recommend the best hybrid cooling system for minimum energy consumption and pollution emissions in buildings according to different parameters is proposed. (C) 2016 Elsevier Ltd. All rights reserved.