Estimation of energy savings resulting from the cooperation of an air to water heat pump with a solar air heater

Abstract

The heating efficiency of a heat pump is strongly dependent on the difference between condensation and evaporation temperature. This article analyzes the combination of a solar air heater (SAH) and an air-to-water heat pump (AWHP) to reduce this temperature difference. A new method for assessing the energy consumption of an air-source heat pump for heating domestic hot water has been developed. It was created on the basis of a model from the EnergyPlus software, simulation results made in the DesignBuilder software environment, and mathematical equations describing the increase in the air temperature in SAH as a function of solar radiation intensity. The authors determined the thermal characteristics of SAH on the basis of experimental measurements carried out in the period from April to July 2022. The test results were interpolated and used in the development of the computational model. Two series of calculations taking into account the preheating of the air in SAH and the supply of AWHP only with ambient air were performed. As a result of the computational analysis, it was found that the maximum reduction in energy consumption by AWHP resulting from cooperation with SAH may reach approximately 16 %.