Awareness of the need for energy efficient houses has never been so high, but are low energy dwellings delivering the performance they promised, or are comfort levels rising?

It is often assumed that commercial and institutional buildings are fairly airtight and that envelope air leakage does not have a significant impact on energy consumption and indoor air quality in these buildings. Furthermore, it is assumed that more recently constructed buildings are tighter than older buildings. However, very little data is available on the airtightness of building envelopes in commercial and institutional buildings.

In designing and constructing its new R&D Centre, the Tokyo Electric Power Company (TEPCO) had two main aims: to provide a comfortable working environment and to conserve as much energy as possible. To achieve these aims, attention focused on the control of heating and lighting, especially in perimeter zones near glazed areas. The major features included ventilation windows with integral automatically controlled blinds, and daylight compensation lighting controls. Together, these have significantly reduced heating and lighting loads

The Elizabeth Fry Building was conceived as a benchmark environmentally benign project, but the design team was allowed no extra capital to achieve this. Could it be done? David Olivier reports

Air speeds at the occupied zone were studied experimentally in seven large railway stations of space volume varying from 540- 9076 m3• The spaces are installed with mechanical ventilation systems and the air supply flow rates are from 0.455-23.67 m3 s-1• Results were analyzed by dividing the measured air speeds into different ranges. Statistical data such as the peak  value, mean value, range of the air speeds and the bandwidth are calculated. Values of the percentage of discomfort were calculated and analyzed similarly.

This paper describes a methodology based on computational and analytical modelling techniques in the prediction of building internal pressure gain functions. It first involves computational modelling of the transient response following a sudden opening, which predicts both the Helmholtz frequency and the damping characteristics fairly accurately. The parameter derived by fitting the analytical model to the computed response are then used in the prediction of the gain function.