Manual Control of Window Blinds and Electric Lighting: Implications for Comfort and Energy Consumption

Abstract

Algorithms to describe the manual control of window blinds and electric light ing, in response to comfort stimuli, were incorporated into a building thermal model. By comparison with fixed control schedules, this paper examines the impact of manual control on model predictions of thermal comfort and build ing energy consumption. For a typical, south-facing office in Toronto, the ther mal comfort of an occupant close to the window was substantially improved by the provision of window blinds. Compared to an office with no blinds, mean PPD (predicted percentage of occupants dissatisfied with the thermal environment) was lowered from 22 to 13%, and overheated hours were reduced by over 200 per year. However, when the lighting was also manually controlled, the blinds imposed an energy penalty. Though reduced solar gain lowered cooling energy by 7%, heating energy increased by 17%, and reduced daylight increased lighting energy by 6 6 %. The implications of these results on the modelling of occupied buildings are discussed.