The specialists of IEA BCS Annex 26 have a clear picture of designer needs. The project objectives have not changes, but emphasis will now be place on the most relevant problems related to air motion, temperature distribution, and energy use. The development of viable solutions by expert teams from twelve countries is primarily based on investigations in existing case-study buildings. Researchers have started to demonstrate advanced experimental and numerical methods at these large enclosures ranging from atria to industrial halls.

The Air Infiltration and Ventilation Centre s Numerical Database has been developed in response to a need to establish a core of numerical data suitable for design purposes and model validation. It has also been developed to provide a focus for

This paper presents the results of a series of measurements made in an occupied family house. Long and short-term measurements of the concentration of radon gas in the cellar and other living areas of the house were carried out. Subsequently a mechanical ventilation system was installed in the cellar and operated in both supply and extract mode with different air change rates. Further measurements of radon concentrations were carried out along with other physical parameters.

In this paper, we investigate the potential of an aerosol-based technique to significantly reduce the leakiness of residential air distribution systems (ADS). The first part is dedicated to a short review of theoretical analyses of particle transport and deposition in an ADS as well as particle removal in the leaks. The purpose of this review is to pre-determine the ranges of the flow rates, pressure differentials and miscellaneous characteristics of the particles that would allow plugging of the leaks in a relatively short time.

A high resolution particle-imaging velocimetry has been developed and applied to study full-scale room air flows. The system is designed to study local field quantities in occupied zones (microclimate), ventilation effectiveness, and airborne pollutant transport in the indoor environment. The system can be applied to evaluate indoor environment in typical commercial and residential settings. The technique and instrumentation have been applied successfully to study localized air flow patterns and particle concentration distribution in the indoor environment.

For the planning of "silent cooling" systems built by free convective coolers, it is necessary to support characteristic data for the cooling performance and the effect of different installation and operating parameters on the cooling performance. At the "Institut für Angewandte Thermodynamik und Klimatechnik" at the University of Essen measurements of the cooling performance of free convective coolers were carried out by using a testing chamber as well an enlarged and modified testing room with dimensions near to practise.

The use of IR detectors to steer the ventilation is in principle an attractive approach for optimising the ventilation according to the occupants needs. In order to evaluate the performances under real conditions, one of the BBRI office buildings in Limelette (some 31 offices with in total 51 persons and a variable occupation load) was equipped with a mechanical supply ventilation system in which each terminal is controlled by an IR detector.

Approved Document (AD Part F1) of the Building Regulations [1] for England and Wales identifies trickle ventilators as an option for providing natural background ventilation in commercial buildings. This paper reports the results of a field measurement study carried out at BRE during the winter of 1994/95 to assess the effectiveness of trickle ventilators. Two occupied office rooms were equipped with trickle ventilators and measurements were carried out for a fortnight period in each office, with the ventilators closed during the first week followed by a week with them open.

A demand controlled ventilation system with humidity as the control parameter was tested in an experimental demonstration project in 16 apartments. In the same housing complex 16 identical apartments with a constant exhaust airflow rate were included in the test as a reference group. The purpose of the study was to investigate whether satisfactory physical health conditions could be reached in the humidity-controlled in apartments, while at the same time reducing the use of energy for heating.

Two factors - CO2 emissions fiom heating and cooling systems and restrictions on the use of CFC refrigerants - have accelerated the development and introduction of new and more environmentally friendly cooling systems. These new cooling systems also include the so-called "Desiccant Cooling Systems (DCS)" [1]. The desiccant cooling systems consist of a rotating dehumidifier, a rotating heat exchanger and evaporative coolers. For design, control and operation of desiccant cooling systems new criteria have to be considered because of the specific properties of these new technologies.