Discusses the accurate evaluation of the effect of thermal bridges on building energy performance using a modelling approach. Sisley software was used first of all to model the heat transfers in the intersections of walls. CLIM 2000 was used to reduce and integrate the models. A comparison was done between these results and the models obtained from thermal regulation values. It appeared that detailed modelling of heat transfers would provide an increased accuracy of around 5% when evaluating the building heat loss.

Gives an overview of a computational approach to the so-called street canyon phenomenon, whereby microclimate influence on thermal loads of buildings and local contribution to temperature rise from air conditioning unit heat emission can affect the heating balance of buildings. Also discusses the influence of flow and temperature fields on the dynamic thermal balance of the building.

Describes the use of a two-layer model to predict mixed convection. It uses a one-equation model for near-wall region and the standard k-e model for the outer-wall region. In six cases its validation shows good agreement between computed and measured data. The model also reduces computing costs.

Proposes a two-layer turbulence model for predicting forced, natural and mixed convection in order to accurately and efficiently simulate indoor airflows. With the aid of direct numerical simulation data, the model uses both a near-wall one-equation model and a near-wall natural convection model.

Looks at two residential flats in a high-rise residential building in Hong Kong using HBT2 detailed building heat transfer simulation software. It analyses the influence of the thermal insulation layer in the outside walls on the yearly cooling load and maximum cooling demand. Tall residential buildings in Hong Kong do not usually incorporate thermal insulation. The simulation predicted a maximum decrease in annual cooling load of up to 6.8%, using a 5 cm thick thermal insulation coating which faced into the flat.

Discusses good control of heating, ventilating and air conditioning systems as the best way to improve energy efficiency in air conditioned buildings. Looks at the Human Science Building at the University of Pretoria in this light. Simulations were performed using QUICKcontrol, a new software tool. Control methods investigated included air bypass, reset control, setback control, improved start-stop times, economiser control and carbon dioxide control. Sixty percent savings were predicted in HVAC power consumption, giving a payback period of nine months.

Analyses present and historical Thai houses in terms of climate, culture and technology, as background to an investigation of the potential for use of natural ventilation as a passive cooling system for new house designs. It suggests that natural ventilation can provide a thermally comfortable indoor environment for 20% of the year. Also develops comprehensive design guidelines for natural ventilation using CFD (computational fluid dynamics).

The residential building described is an experimental low energy home, using a hybrid system with natural energy resources and unused energy. Describes its construction and evaluation. Added features include superinsulation and good airtightness, with a calculated heat loss coefficient of 0.97 W/m2K. Passive systems include direct solar heat gain and exhaust stack ventilation. Renewable energy systems include PV modules, wind power and domestic hot water, and a ground source heat pump for both heating and cooling. There is a floor cooling system for summer cooling.

A study obtained steady-state solutions for Rayleigh number on flow structure of buoyant flow in a roof of triangular cross-section. The heat transfer was also investigated. It was found that height-base ratio and Rayleigh number have a significant influence on the temperature and flow field.

Describes how a computational fluid dynamics code was used to predict temperature and flow fields in recessed spaces outside high-rise residential buildings housing condenser units for window air conditioners. Attempts to analyse how heat is rejected into the spaces, which differ in height and location of unit. A strong rising hot air stream and one vortex pair were identified in the space near to the corner wall. It was also found that condenser units operate poorly when placed inside the taller recessed space, and at higher locations and nearer to its corner wall.