Paper Conference

Proceedings of eSim 2008: 5th Conference of IBPSA-Canada



A. Laouadi, A. Galasiu, M. Swinton, M. Manning, R. Marchand, C. Arsenault, F. Szadkowski

Abstract: Recent statistics published by Natural Resources Canada estimated that the energy demand for heating and cooling accounts for about 63% of the total energy use of an average Canadian home. Although the overall demand for cooling energy is much lower than the demand for heating, many populated areas experience a peak demand for electricity on summer afternoons. Exterior window shading devices have the potential to reduce solar overheating in summer and heat losses in winter, and to improve the thermal comfort of the house occupants when seated near windows, compared to interior shadings. This work is part of a project which aims to develop guidelines for effective exterior, mid-pane (inside the window) and interior shading devices in Canadian residences. This paper reports on the first winter field measurements of exterior rollshutters at the Canadian Centre for Housing Technology. Exterior insulating rollshutters were installed on the windows of a typical, four-bedroom, two-storey detached house and were compared to interior blinds installed in an identical neighbouring house. In both houses, the shading devices were open during daytime hours to let solar heat in and were closed during night-time to reduce window heat loss. The results from two weeks of measurements showed that the rollshutters reduced the window heat loss by 19% compared to interior blinds. This heat loss reduction was translated into savings of about 4±2% in furnace gas use. The window internal surface temperature was about 3 o C to 5 o C higher when covered by rollshutters than when covered by interior blinds. This indicates a significant reduction in the risk of moisture condensation on the window interior surface.
Pages: 127 - 134