Residential building performance analysis at near extreme weather conditions in Hong Kong through a thermal-comfort-based strategy

The precise building performance assessment of residential housings in subtropical regions is usually more difficult than that for the commercial premises due to the much more complicated behavior of the occupants with regard to the change in indoor temperature. The conventional use of a fixed schedule for window opening, clothing insulation and cooling equipment operation cannot reflect the real situation when the occupants respond to the change in thermal comfort, thus affecting the appropriateness of the assessment results. To rectify the situation, a new modeling strategy in which the modification of the various operation schedules was based on the calculated thermal comfort (TC), was developed in this study. With this new TC-based strategy, the realistic building performances under different cooling provision scenarios applied to a high-rise residential building under the near extreme weather conditions were investigated and compared. It was found that sole provision of ventilation fans could not meet the zone thermal comfort by over 68% of the time, and air-conditioning was essential. The optimal use of ventilation fans for cooling could only help reduce the total cooling energy demand by less than 12% at best which could only be realistically evaluated by adopting the present strategy. Parametric studies were conducted which revealed that some design factors could offer opportunities for reducing the total cooling energy under the near extreme weather conditions.