At present the design pressure difference for air inlets in The Netherlands is 1 Pascal. This paperinvestigates the question whether or not this value is still appropriate.In recent years the airtightness of dwellings has improved remarkably. Self adjusting air inletshave been introduced on the market. What is the effect of these changing building features onthe pressure difference over the building envelope?

In France, the regulation on residential building ventilation is based, since 1969, on a generaland continuous air renewal ; the fresh air comes into habitable rooms by air inlets and thestale air is drawn out to exhaust vents in the service rooms. So the air inters the habitablerooms crosses through the dwelling, is extracted in the service rooms.The Research and Development Division of Gaz de France and the CSTB have studied theneeds in each room of a dwelling (depending on the size and the occupancy) to perform newventilation system(s).

This paper presents the results of ventilation measurements taken in a non-occupied one-storey dwelling situated in the countryside. The measurements of the ventilation rates in the different rooms have been obtained by the use of tracer gases with the constant concentration technique. Four configurations of ventilation systems have been tested successively. The ventilation systems tested consist of natural air supply and mechanical exhaust. Both 'normal' air supply grilles and self-regulating grilles have been tested.

A Tool Kit was developed to assess indoor air quality. The Tool Kit was designed to be robust, reliable, universal and to provide data that could be linked with other studies assessing health, social factors and building conditions for any given locality. A case study using the Tool Kit to assess 116 Local Authority houses is described.

Infiltration has traditionally been assumed to affect the energy load of a building byan amount equal to the product of the infiltration flow rate and the sensible enthalpydifference between inside and outside. However, laboratory and simulation research hasindicated that heat transfer between the infiltrating air and walls may be substantial, reducingthe impact of infiltration.

The prediction of energy use, air flows and temperatures in different rooms of a building andat different climatic conditions is very important, especially when evaluating new conceptsfor heating and ventilation systems in combination with different building envelopeconstructions. A thorough system analysis considering coupled air flow and thermalcalculations becomes very complex if e.g. thermal bridges and dynamic conditions areconsidered.

The paper presents a short description of the measurement program and the data collected for the “SynergieHaus”-project initiated by PreussenElektra and partners (now merged to E.ON). Results of airtightness measurements (ACH 50-values) are shown for a to

In the recent past new concepts for the building envelope have been developed with theunderlying wish to improve the energy performance of a building as well as comfortconditions in the inner spaces. Examples are: solar walls, high-tech window systems, doublefacades and integration of daylighting systems and of PV-panels. In this paper the doublefacade concept is discussed.This kind of facade is considered as a device to be used for pre-heating the ventilation airduring winter as well as for nocturnal cooling of the building during summer.

The move towards improving building air-tightness to save energy has increased theincidence of poor indoor air quality and associated problems, such as condensation onwindows, mould, rot and fungus on window frames. Mechanical ventilation heat recoverysystems (MVHR) combined with heat pumps offer a means of significantly improving indoorair quality as well as providing heating and cooling required in buildings.This paper is concerned with the testing and performance of a novel ventilation heat pumpsystem developed for the domestic market (1,2,3).

In 1998 the Dutch ventilation industry launched a new generation of domestic ventilation systems on the market with high efficiency heat recovery applying counter flow heat exchangers and DC fans. It is expected that these ventilation systems will play an important role in realising the goals of the Dutch national energy policy for reducing energy use in the built environment. Another important aspect is the contribution to a healthy indoor environment in dwellings with an extreme high energy efficiency, especially in relation to increasing air tightness and thermal insulation.