Experimental assessment of the energy performance of a renewable air-cooling unit based on a dew-point indirect evaporative cooler and a desiccant wheel
Energy demand for space cooling will more than triple by 2050 – consuming as much electricity as all of China and India today. Under this scenario it is required the development of innovative sustainable and renewable cooling technologies. The TEP974-RATE research group at the University of Cordoba has developed and tested a new prototype called RACU (Renewable Air-Cooling Unit) within the framework of the H2020 Wedistrict research project, to be integrated into renewable District Heating and Cooling Networks (DHCN).
The main objective of this work was to experimentally study the energy performance of this prototype. RACU is composed of two main technologies: a Dew-point Indirect Evaporative Cooler (DIEC) and a Desiccant Wheel (DW) to independently control the air temperature, air humidity and indoor air carbon dioxide levels. An extensive number of experimental tests (N1-N64) were carried out to fit an empirical model of RACU, focusing on outlet air conditions and the coefficient of performance. In addition, several performance indices were developed for DW and DIEC.
The highest values of dehumidification capacity, sensible cooling capacity and coefficient of performance for RACU were achieved for the most severe outdoor air conditions, namely 19.02 kg⋅h-1, 21.49 kW and 11.0, respectively.
The main findings were that RACU offers an opportunity for improving energy efficiency, thermal comfort, and indoor air quality in buildings. This experimental work can also serve as a reference for research on the feasibility of innovative hybrid air-cooling systems under heat events and the climate change world scenario.