Simplifying energy performance assessment in the Hong Kong building environmental assessment method

In the Hong Kong Building Environmental Assessment Method (HK-BEAM) for air-conditioned office premises, energy use for air-conditioning constitutes one major item of assessment. The current assessment method for existing offices is based on computer simulation predictions. Following a recent review of the HK-BEAM scheme, simplified models have been developed for use in the assessment as an alternative to the detailed simulation method. These models are multiple linear regression models relating the annual electricity use for air-conditioning, and the maximum electricity demand, in an office building to the key characteristics of the building envelope and the air-conditioning system. Use of these models can reduce the effort required for data collection and input, and will allow the assessors to more quickly complete an assessment. In addition, additional parametric studies can be performed within much less time, which will help assessors in formulating advice to developers/designers on measures that wil l lead to improved energy performance and thus higher credits. This paper summarizes the review findings and describes the approach taken in the establishment of the regression models. Comparison of predictions by the detailed computer simulation method and the alternative method showed that the latter could provide estimates close enough to the simulation predictions for the purpose of assessing the credits to be awarded to a building for its energy performance.