Lu Aye; Chaichana, C & Charters, WWS 2006 (Accepted 3 November 2006) 'Propane as a working fluid for solar boosted heat pump', ICGSI2006, International Conference on Green and Sustainable Innovation: Integrated Approaches for Sustainable Society, 29 November - 1 December 2006, Chiang Mai, pp. 405-11.

Abstract

Heat pumps have been used in heating applications due to their ability of upgrading low-temperature energy to a high-temperature heat at high energy efficiency. One of the current heat pump applications is domestic water heating where the heat sources of the heat pump water heater are ambient air and solar energy. These heat pumps use R-22, which is one of the ozone depletion substances, as a working fluid. This study explores the possibilities of replacing R-22 with propane (R-290), a natural working fluids in solar-boosted heat pump (SBHP) water heater. The experimental rig consists of a solar-boosted heat pump, which is bought off the shelf. It was found that R-290 could be used as direct drop-in replacement for R-22 with only minor modifications to the existing heat pump. The results from the experiments showed that the R-290 heat pump has a higher COP than that of the R-22 heat pump by about 7 per cent.

Keywords: Heat pump; Solar energy; Working fluid; Propane; Replacement for R-22.