Builders across the United States are seeing strong sales of homes that can reduce heating and cooling bills by as much as 50°/o but cost about the same as conventional homes to build. In the process of designing, building, and analyzing these homes, they've learned lessons about systems engineering that all builders can put into practice.

Natural ventilation is a sustainable, energy-efficient and clean technology that is well accepted by occupants. It can be used to provide fresh air for occupants as necessary, to maintain acceptable air quality levels and to cool buildings in cases where climatic conditions allow. The successful application of natural ventilation techniques and the effectiveness of natural ventilation are determined by the prevailing outdoor conditions and microclimate as well as by building design and building use.

The use of ceiling mounted circulating fans to provide air movement for cooling in industrial premises and animal houses is particularly essential in warm, humid climates. Methods to substantially improve the efficiency of this approach are demonstrated in this paper. Fan laws are identified as one source of strategies for increasing energy-efficiency of fans. Industrial ceiling fans are used to demonstrate that using larger, slower, fans will not only improve energy efficiency but also reduce fan noise.

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