A simulation of solar shading control on UK office energy use

The energy and thermal comfort implications of installing solar shading are examined, including automatically controlled shading. An air-conditioned office was simulated using a sophisticated environmental modelling program (DOE-2) for a range of shading and control systems. These comprised manually controlled internal blinds, a fixed external overhang, and internal or external blinds under automatic control and manual override. Results suggest that in England shading can result in reductions in carbon dioxide (CO2) emissions and energy cost, where office buildings are air-conditioned. Additional CO2 savings were obtained with automatic control of shading, of around 3% compared with simple manually controlled or fixed systems. The benefits of shading are latitude dependent; in Scotland, installation of external shading gave an energy penalty of between 1% and 9%. Moveable external shading gave the highest energy penalty because occupants would use the external blinds to control glare, reducing solar gains on cloudy days. Automatic control of internal shading was more successful here, reducing CO2 emissions by around 3% compared with manually controlled internal shading.