English

Dynamic computer simulations were used to compare residential ventilation methods to identifyan approach that would improve indoor air quality with minimum energy penalty while maintainingcomfort.

Before starting to design an HVAC installation for treatment, supply and exhaust of air to and from a building the needs should be listed, transformed to requirements and their consequences analysed. Requirements lead to different amounts of airflow for their fulfilment. These needs for airflow should be calculated. The demand leading to the highest call for airflow will decide the airflow for which the equipment should be dimensioned - the dimensioning airflow.

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 this paper, the ventilation of a “crêpe” paper-processing workshop containing dryers, which generate a high thermal load, is considered. Displacement ventilation has been used for many years in industries with high thermal load. The main ventilation de

Measurements of ventilation rates and internal temperatures have been recorded in a naturallyventilated auditorium with high intermittent heat gains for a wide range of weather conditionsat a UK site. Satisfactory internal temperatures and high ventilation rates have been found forwinter, mid-season and summer external conditions.Simple ventilation and thermal models have been derived from experimental data whichallow the prediction of ventilation rates and internal temperatures within the auditoriumdespite the complex natures of the flow regimes and heat transfer mechanisms present.

In this study, we investigated the indoor air quality (IAQ) in classrooms with exhaustventilation systems and in naturally ventilated classrooms. In the latter, we found peak CO2-concentrations of more than 4000 ppm. 1500 ppm was exceeded during 40 to 86% ofteaching time, dependent on class size. The windows were opened rarely in winter which ledto low mean air exchange rates of 0.20 0.23 h^-1. The operation of mechanical ventilationsystems improved IAQ considerably. Peak CO2-concentrations decreased to less than 2500ppm. 1500 ppm was exceeded for only 7 to 57% of teaching time.

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.

Dwellings airtigthness is not well known in practice, in France.When dwellings are equipped with mechanical ventilation systems (which represents about 95% of the new dwellings in France) the airtigthness can strongly influence the performance ofventilation.In the frame of the European Joule Project TIP-VENT (Towards Improved MechanicalVentilation Systems) [1], measurements of airtightness and underpressures were made onthree multifamily buildings.

In this study a series of parametric laboratory measurements were made of the velocitiesoutside, ve, and inside, vi, a full-scale louver positioned in a rectangular opening located in avertical wall forming part of a 1m x 1m x 2m deep model room. The louver parametersexamined, for external incident wind speeds from 0.6 to 2.5 m/s, included louver blade depth(L), aperture (d) and distance from the louver in to room (Rd). For this initial study the bladesof the louvers for each experiment were horizontal with an inclination angle ? of 0.

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.