The experimental part of the study of the reverse cycle defrosting performance on a four-circuit outdoor coil unit in an experimental 6.5kW heating capacity residential ASHP has been reported in Part I of a two-part series. The experimental results indicated that downwards flowing of the melted...

When an air source heat pump (ASHP) unit operates in heating mode, frost can be accumulated on the surface of its finned outdoor coil which normally has multiple parallel circuits on its refrigerant side for minimized refrigerant pressure loss and enhanced heat transfer efficiency. On its...

Usually, a medium such as water and electrical current is transported through an energy distribution network for delivering energy. Driving the medium through the network will lead to power loss. In this paper, a fundamental study was conducted to find out the optimal/near-optimal shape of an...

Reverse cycle defrosting is the most widely used standard defrosting method for air source heat pump (ASHP) units. It was suggested in previous experimental studies that during reverse cycle defrosting, downwards flowing of the melted frost due to gravity over a vertically installed...

Being environmental friendly and with the potential of energy-efficiency, more and more ground-source heat pump (GSHP) systems are being widely used. However, the influence of groundwater advection on the performance of the geothermal heat exchanger (GHE) in a GSHP is not still clearly known. In...

A novel dry-expansion shell-and-tube evaporator (DESTE) integrated with function of defouling was developed as a component of wastewater source heat pump (WWSHP). To compare the performance of the DESTE-WWSHP with the conventional immersed evaporator (IE) based wastewater source heat pump...