Study of water-filled double-glazing with submerged heat exchanger for solar absorption

Water-filled window with submerged heat exchanger is a new solar-absorbing multi-glazing system. The device is able to heat up services water and reduce room air-conditioning consumption simultaneously. An experimental prototype was constructed and its thermal performance was examined. Based on this prototype, a dynamic simulation model for investigating energy performance was developed. The computational accuracy was verified by comparison with measured data. The numerical model was then used for performance evaluation with a range of environmental conditions. The numerical evaluation showed that for warm-climate operation the water-heating efficiency could be more than 20% during the daytime. Water heating may even continue at night, if the operating conditions are favorable. Further detailed analysis is then suggested to assess the thermal characteristics and the energy-saving potential under realistic application scenarios.