Energy related performance of manual shading devices in private offices: An occupant behavior-based comparative study using modeling approaches

Abstract

This paper aims to answer whether and to what extent energy standard based shade assumptions over predict energy and economic performance for the hot summer and cold winter zone of China using modeling approaches. Occupant behaviors on shade action, occupancy and related lighting, office equipment and heating/cooling operation were considered and the energy and economic performances of manual shades were compared with standard assumption. Results show that annual energy uncertainty is significant, indicating a high uncertainty of energy performance. Standard assumption about occupant behavior adopted by building energy codes leads to an over prediction of energy saving by about 3 times compared with behavioral models. An interesting finding is that using manual shades may result in an energy increase (the probability is 7.26%) rather than energy saving. Meanwhile, net present value analysis shows that there is a significant overestimation of economic performance by shade behavior model alone as compared to occupancy plus shade models, and may lead to a biased economic prediction or even an inappropriate design decision on manual shades. A proposed shade behavior improvement strategy shows that it not only has a more robust shading performance but also a lower energy demand.

Keywords

• Building energy
• Occupant behavior
• Manual shades
• Economic performance
• Uncertainty