MODELLING BUILDING PERFORMANCE

This paper describes the application of modeling for predicting energy and environmental performance of buildings. Two area of modeling will be discussed. Computer modeling enables the performance of buildings to be predicted at design stage. The dynamic building energy model HTB2 has been developed at the centre. This can be used to predict seasonal energy performance on an hourly time-scale, taking account of the building construction , its occupancy and its location. Examples will be given of the use of HTB2 for research and design consultancy. HTB2 is used in the Hong Kong building environmental assessment model , HK-BEAM, for office buildings. CFD to predict natural and mixed-mode ventilation performance will be described. Scale modeling of buildings in a boundary layer wind tunnel can be used to predict wind effects on ventilation performance. Examples will be discussed with reference to case studies of offices on ventilation performance spaces. The pressure coefficients measured in the wind tunnel can be used as boundary conditions for CFD predictions of ventilation performance. The impact of daylight and sunlight on building design can be modeled in an artificial sky/ heliodon. The newly constructed8 m diameter domed sky at the Centre will be described and examples given of its use.