There has been a recent growth of interest in the use of passive cooling in buildings, particularly in the use of chilled ceilings, including both beams and radiant panels. However, there is still concern about the risk of condensation on cold surf aces and water dripping onto occupants or furnishings, especially where there is no control over the level of humidity for instance in naturally ventilated buildings.

This paper reports the findings of a pilot field study carried out to investigate the internal and external pollution levels in two buildings, one naturally-ventilated and the other air-conditioned and to investigate their relative attenuation of external pollution levels. The study is a precursor to more extensive studies aimed at providing guidelines for the design of energy-efficient buildings with a good indoor environment in urban areas.

Computational fluid dynamics (CPD) modelling is increasingly being used as a tool for predicting ventilation rates and air flow patterns as part of the building design process. The potential benefits of this form of modelling are that designs can be optimised to make the most efficient use of ventilation, and so to increase air quality and decrease energy use. Although CFD has shown itself to be a powerful tool in the nuclear, aeronautical and electronics industries for over two decades, its reputation has been built on extensive work specific to those fields.

BRE, working with a group of industry and property representatives, have developed a simple method for assessing the likely energy efficiency of air conditioned and mechanically ventilated buildings. For new buildings, the method uses information available at the early design stages. It therefore provides designers with a tool to assess the implications of various plant and envelope options from the beginning. It can be used as a label or target for energy efficiency and, as such, as a means of assessing buildings in both voluntary systems such as BREEAM or perhaps in Building Regulations.

The BRE is developing an energy rating scheme for non-domestic buildings on behalf of the DoE, designed to encourage voluntary good practice and for possible future use within the Building Regulations. The scheme will allow building specifiers, occupiers and others to define and compare building performance in simple. terms. The UK programme is in its early stages, and a key part of its technical development and implementation involves consultation with a wide range of potential users. This paper outlines the policy and commercial needs driving the programme.

Interest in the UK regarding the design of passively ventilated and cooled buildings has resulted in much work on the thermal performance and likely environmental impact of such buildings. Little work assessing the impact of the passive design approach on the construction process has been undertaken. This issue is examined herein, through the initial development of a methodology quantifying the relationship between passive environmental control (PEC) and the construction process, leading to a means of classifying buildings according to their prefabrication strategy.

Thermoeconomics is a blend of thermodynamics with economics. The thermodynamic analysis uses the second law and the concept of exergy, the measure of usefulness of energy. Economics involves costing exergy flows in life costing techniques. The objective of thermoeconomics is to minimise a cost function, talcing into account capital, maintenance and running costs. Most of these are expressed in terms of thermodynamic variables of the system. This will establish the most cost effective design parameters.

The purpose of this paper is to present the energy required to condition a constant volumetric airflow and determine the variability of this energy due to changes in the design dry bulb and humidity setpoints. Hourly weather data from a typical year from 32 European locations and long-term data from 11 American locations were analyzed to determine the coincident dry-bulb and dew-point temperatures. These data were then analyzed to determine the heating, cooling and moisture removal energy requirements for a constant mass of airflow per hour.