PV Driven Dew-Point Cooling for Australia
Abstract
Dew-point cooling devices use the principles of evaporative cooling to provide air-conditioning with very high electrical efficiency. Although commercial products are available, they are yet to gain mainstream acceptance in the residential cooling market. One factor has been a lack of clarity around the climates for which they’re suitable. This is undoubtedly complicated by the fact that cooling demand varies greatly between different buildings even within the same climate. In addition, the economic benefit due to lower running costs may be off-set by a higher initial purchase price. If dew-point coolers (DPC) are to compete on price alone, any economic benefit needs to be very clearly communicated. A complicating factor is the advent of dedicated solar PV driven, and PV-battery driven air-conditioners. Given that DPC’s require less electricity to provide the same cooling, this should translate to a reduction in the required PV-battery system size. Here we analyse the ability of DPC’s to provide complete comfort in different combinations of Australian climates and buildings, both for grid-connected and off-grid PV- battery applications, as well as the economics of both these systems in comparison to conventional vapour- compression air-conditioners. Results show that a DPC can provide complete comfort for approximately half the Australian population; that a 5kW grid-connected cooler is economic in key climates at an installed cost of $2000, and that an off-grid PV-battery driven DPC is currently not economically viable.