A self administrated questionnaire was mailed to over 300 dwellings in blocks of flats usingthe wall exhaust. In almost all the dwellings there was a controllable ventilation unit. Theunits were either a mechanical exhaust ventilation system type with outdoor air inlets ormechanical supply and exhaust ventilation system with heat recovery and outdoor air intakeon the wall. In the questionnaire, the daily use of ventilation unit, noise levels as well as odorsand their sources in the dwellings were asked.

In this study, we have tested more than 80 silencers of different sizes (from O 250 to 1250), length, insulating thickness and with or without central pod. The attenuation, measured at several velocities between 0 - 8 m/s, was compared to some literature estimations and has shown strong differences. They induce that literature estimations should be used only in the same conditions they were made and, not too widely, as it is currently done because real knowledge of the influence of parameters is lacking.

The inadequate dissipation of hurnidity fiom living spaces and bathrooms has become asignificant problem area in recent years. This can be attributed both to the replacement of old,poorly sealed windows by new windows with better seals, and to the increasing use of tilesand other building materials which hinder an adequate absorption of water vapour.The residents tend to reject repeated opening of the windows for ventilation purposes ongrounds of the ensuing energy costs.

A wind tunnel study was carried out to investigate the airflow through courtyard and atrium building models. Ventilation strategies resulting from the use of different atrium roof pressure regimes (positive pressure and suction) were examined and compared with the performance of the open courtyard. The model buildings were monitored both in isolation and in idealised urban environments of varying group layout densities. The effect of wind direction was also observed.

The trend 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 1 heat recoverysystems combined with heat pumps offer a means of significantly improving indoor airquality as well as providing heating and cooling required in buildings.This paper is concerned with the development of a novel ventilation I heat recovery systemfor the domestic market1.

A computational study had been carried out on hot and cold air interaction across the door of an urban transport vehicle. The studies show that within 20 s after the door is opened all cool air beside the door of the vehicle would flow out when the amb

The efficiency of a kitchen ventilation system is usually determined by its ability in heat and effluent removal. The main part of a ventilation system is the hood, with its face (or capture) velocity. Heat generation associated with the cooking process is the main factor that affects the thermal comfort. The heat removal capability is studied under different capture velocities so as to determine the minimum requirement for efficient removal of heat and effluent.

Airtightness measurements are not yet common in the Italian dwelling stock. In the frameworkof the MICA-ENEA contract, three dwellings were chosen to study the energy performanceon the influence of natural agents. The majority of the dwellings in Italy still nowdays rely onnatural ventilation and records of the fluidynamic and energy performance are not contractualdocuments among the parties involved.

A systematic analysis of recently constructed dwellings in the Flemish Region has been undertaken within the SENVVIV-project (1995-1998). In total 200 dwellings have been examined in detail. The study involved various aspects: energy related building

Filters used for general ventilation are mass produced and tested by type at rated airflow rate in order to determine the evolution of the pressure drop and the efficiencies during an artificial and shortened clogging process. For filters of better quality it is necessary to evaluate the efficiency concerning fine dust: the traditional atmospheric dust spot efficiency method is now being substituted with an innovative method which allows one to determine the fractional efficiency versus the particle diameter within a 0.2 divided by 3 um range.