Manufacturing and performance testing of hybrid air conditioner water heater (H-ACWH)

Abstract

Air Conditioner Water Heater (ACWH) is a technique of recovering generated Heat Waste within refrigerant cycle on a running Air Conditioning System. Heat transfer occurs from high-temperature refrigerants after exiting the compressor outlet to the water which has a lower temperature in water storage tank. With this transfer of heat, it is expected to decrease the refrigerant temperature and increase the temperature of the water inside the storage tank. There are several specific studies regarding ACWH design. Specifically, in University of Indonesia (UI), the previous studies and researches on ACWH design were only focused on investigating the performance of each Heat Exchanger design. This research was carried out on a Hybrid Design focusing on the water temperature output. Although the design of Heat Exchanger used (Serpentine Heat Exchanger) in this system was still the same used in the latest ACWH studies conducted in UI, there are several key differences in the Hybrid ACWH system. First, the water in the storage tank has been pre-heated beforehand with the help of Solar Heat Collector. Thus, this method should expect a higher final value of water temperature and should provide a backup solution when the AC system is not running, fulfilling the need of hot water availability at any time. The second difference in this H-ACWH system, the water storage tank is designed to have a space filled by PCM material between the outer shell of the tank and Aluminum Foil. The purpose of this implementation of PCM, along with the conventional insulation technique, is to further conserve the heat inside the tank by recovering possible heat loss with the latent heat of the PCM. The third difference is that in this H-ACWH system, there will be no electric water pump regulating water flowrate. This system will only rely on gravitational water. The results obtained in this study are expected to be higher final Hot Water temperature, a reliable Hot Water source system that can be implemented into Net Zero Energy Building concept as the system does not need any additional fossil or electric energy to run.