1.1. General specifications

The PVT system modelled uses air as the heat transfer fluid, drawn through a duct at the rear of the PV modules, and has a glass cover. In winter, air is drawn past the rear of the photovoltaic panels and ventilated into the house. In summer, it is envisaged that air would be drawn in from underground using an air/earth heat exchanger and the heated outlet air would be ventilated to the outside, however, this is not investigated here. Such an earth/air heat exchanger would also be used during winter. In this modelling only the household heating was examined and for simplicity the outdoor air was used as the inlet air for the PVT system.

The example house used for modelling is an existing 100m2 single storey three bedroom house located in Sydney for which the floor plans and building construction details were obtained. This house was modelled with two zones (a north and a south facing zone) and internal thermal mass in which the heat delivered by the PVT system during the day would be stored for release overnight. The house is reverse brick veneer construction with standard brick forming the internal wall layer, followed by 20cm bulk insulation and external cladding giving an R-value of 5 m2K/W. The windows used for modelling were double glazed with a low emissivity coating giving an R-value of 0.5 m2K/W. The roofing material was steel and the ceiling was also insulated with 20cm of bulk insulation to an R-value of 4.5 m2K/W. A timber floor is suspended above an enclosed crawlspace and is insulated with 12cm of bulk insulation to an R-value of 3 m2K/W.