Performance study of CO2 heat pump under tropical conditions of Singapore

• Main Authors: Soh, Alexander, Dubey, Swapnil
• Other Authors: Energy Research Institute @ NTU (ERI@N)
• Format: Article
• Language: English
• Published: 2019
• Subjects: Science::Physics; Heat Pump; Residential Water Heating
• Online Access: https://hdl.handle.net/10356/90076; http://hdl.handle.net/10220/49406
• Institution: Nanyang Technological University

In tackling the rising energy consumption incurred in residential water heating applications in Singapore, alternatives to traditional water-heating systems, which account for one-fifth the energy consumption of an average household, are being explored. One such alternative is heat-pump water heaters, which have been gaining ground in Singapore market. However, most conventional heat-pump water heaters using traditional refrigerants such as R22 or R134a, which could not reach temperatures high enough for comfortable use for showering and baths without compromising efficiency. In this study, a commercial heat-pump water using Carbon Dioxide as the refrigerant in a transcritical cycle was experimentally studied at heating temperature of 65oC and 80oC to evaluate the impacts of tropical climate on its performance. Average coefficient of performance (COP) of CO2 heat pump for tank heating temperature of 65oC and 80oC was found to be 5.4 and 3.8, respectively.