A major concern of those wishing to limit the energy use in buildings is the growing trend towards installing air-conditioning in new and refurbished buildings. Building design, high thermal loads, and a desire for perceived comfort, contribute to an ever-growing demand for full air-conditioning. Therefore, to counter the impact on building energy use, it is essential that building design and operation is developed to minimise the use of air conditioning systems.

The performance of a Ventilated wall component under real weather conditions was tested, during two weather seasons, winter and summer. The component was built in a 1:1 scale, consisting of two equal area parts, a Ventilated wall with and without a radiant barrier. It was installed at the South faade of a PASSYS outdoor Test Cell at CRES. Air openings were located at the bottom and top of each wall component in order to facilitate the air movement through the air gap.

Dynamic insulation is a very good example of a ventilation system integrated with the building envelope. The paper describes two recent studies carried out at Nottingham on dynamic insulation. One study concerns a system based on mechanical ventilation. The other describes a purely natural system. Although there are few existing applications of dynamic insulation, it is argued that there is potential for both systems, particularly with certain types of building. The natural system is technically more challenging than the mechanical system, but the potential energy savings are larger.

This paper briefly exams the role of the building envelope in determining the internal environmental conditions in buildings and the scope for holistic design of building services and building envelope. It then looks at how holistic design may be undertaken, the barriers to be overcome to enable this to happen and the incentives that are necessary.

In this paper, measurement and simulation results are presented that demonstrate the energy performance of a recently built ecological house in Helsinki, Finland. The space heating energy consumption was measured to be 76 kWh/(m 2 ?a) of which 29% was provided by wood. For comparison, Finnish houses typically consume 120 kWh/(m 2 ?a) or nearly 60% more energy for space heating. The total energy consumption (121 kWh/(m 2 ?a)) and electricity consumption (28 kWh/(m 2 ?a)) were quite low.

Ventilation performances in existing buildings are not well known, in France. They are not often checked. This paper shows how a method for checking the performance of ventilation could be applied in France. Such a method, mainly based on visual inspections and simple measurements has already been used for years in Sweden. The Swedish method has been tested in France, in collaboration with a Swedish inspector, on different commercial buildings of different sizes and ages : two secondary schools, one primary school, one office building, one hotel and one bar.

The main problem in natural ventilation is that its efficiency depends very tightly on the meteorological conditions : high wind velocity and outside temperature lower than inside are optimal conditions for efficient ventilation. Consequently, air renewal inside buildings is very fluctuating from one moment to another, and extreme comportments can be reached from one season to another : in winter, ventilation is usually very satisfying, whereas in summer unwanted reverse airflows can hardly be avoided.

Following calculations of potential energy savings, several types of earth-air heat exchangers have been coupled to buildings in novel concepts for passive heating and cooling of ventilation air. For the first time this technology was used in the Belgian climate. In a first case one short plastic tube is coupled to the HVAC system of an office building, to preheat/precool the fresh ventilation air. Measurements are presented on this system and it is shown that performance could have been improved by more concern during the design stage.

Air filters may be used to reduce indoor airborne concentration which is one of the main indoor air pollutants. Air filters performances have to be measured in order to be able to select the right product for a given application. But differences do exist between laboratory and field filter test results and HVAC installations have to be controlled regularly. EUROVENT 4/10 recommendation describes guidelines for the evaluation of the perpromances of HVAC air filters according to particle size in an installation.

This paper summarizes part of the work held at ENTPE within the framework of the IEA Annex 35 project. The aim of the work is to develop and experimentally evaluate control strategies for hybrid ventilation systems to provide comfortable indoor environment and good air quality by combining the best aspect of natural and mechanical ventilation. To reach this target and asses the physical model elaborated in this project, a test cell "HYBCELL" has been designed within the laboratory.