Performance of a solar-assisted thermodynamic heat pump for water heating

Abstract

Malta’s domestic sector predominantly consume electric energy for the provision of comfort and operation of services within households. About 30% of the total national consumption is used by households, with the potable hot water production accounting for 24% of that energy. Nowadays, the major part of households heat water using an electric boiler, with an overall efficiency of 0.75. The EU Directive on Energy Efficiency 012/27/EU and the Renewable Energy Directive 2009/28/EU, as well as the Energy Performance of Buildings Directive 2010/32/EC, have all identified energy use in buildings as the primary area where energy saving may have technically-sound and cost effective results. This paper focuses on the use of a thermodynamic heat pump for the production of potable hot water, which would reduce the electrical consumption in households. The Solar-Assisted Thermodynamic Heat Pump (SAHP) produces hot water using the primary energy source of solar energy and ambient air. Such a system is new to Malta and no local testing has been carried out to gauge its performance under local conditions. In this paper the potential application of a unitary type direct-expansion SAHP (DX-SAHP) system was examined. Testing was carried out during the most critical months between November and January.