In many existing ventilation systems unintentional reentrainment of pollutant, due to improper location of exhaust and air intake, decreases quality of indoor environment. Unfortunately, the more precise method of assessment of exhaust plume behaviour, the more difficult potential application in regulatory codes and standards. The aim of the paper is to discuss advantages and disadvantages of different types of the models and their applications in regulatory requirements.

The paper presents further then an integrated model the supporting methodology that allowsto assess natural urban ventilation conditions both outside and inside constructions.Though some particular aspects arid procedures can be complex and time consuming thegeneral structure is quite simple:1. to establish wind regimes as a boundary condition - information can come from windmeasurements at undisturbed areas Like airports;2. to integrate these regimes within the site - using numerical models to transfer information tothe site;3.

From an air pollution study in a medium-sized, seaside town in Central Greece (Volos) it wasfound that some common air pollutants (CO, NO, NOx, SO,, 0,), whose emissions are connectedto activities and conditions that reveal some characteristics of periodicity on a daily,weekly or yearly basis (e.g.: production activities, meteorological conditions), are monitoredin the atmosphere in concentrations that reflect this periodicity.

To conduct a controlled trial to test the ability of a newly developed electrostatic air cleaningtechnology (EAC) to improve Indoor Air Quality (IAQ) as defined by levels of air borne particlesand to investigate the potential to reduce non-attendance rates due to illness among children intwo Swedish day care centres.

Modelling of indoor pollutant concentrations that varies in time can be a useful tool forestimation of the strength of internal sources and sinks. Usually the modelling has beencarried out using one zone, i.e. with the assumption that the air is well mixed [1,2,3]. Thepresent paper demonstrates that the methodology may be modified to fit multizone situations.By studying the decay of a tracer gas, a correct model can be obtained for a specific volume ina building.

This study describes how the air quality in a displacement ventilated classroom can beinfluenced by the position of a contaminating person, and by the activity of a person who walksaround in the room. Tracer gas measurements have been performed in a full scale mock-up of aclassroom, with person simulators at the student's desks.The spreading of contaminants from a person seems to be strongly dependent on the positionof the person. The closer the contaminating person sits to the outlet terminal(s), the less ofhishers contaminants are spread in the room.

In this paper ventilation strategies are examined in order to improve the thermal performanceof an attached sunspace of a two-storey semi-detached house in the area of Athens Greece.The ventilation strategies examined are cross and single-sided ventilation through the verticalwindows of the sunspace. Simulations were conducted implementing multizone ventilationmodel COMIS coupled with the thermal simulation model Suncode.

This paper is concerned with heat and mass transfer through two typical staircases, The firststaircase connects the two individual floors of a two-storey building, and the other connectsthe three individual floors of a three-storey building. A series of experiments have beenperformed in order to study the buoyancy driven flow between the floors. A single tracer gasdecay technique was adopted . Temperatures at various points on each floor were constantlymonitored and air velocity measurements were also provided at some specific locations.

The goal of this project was to improve the quality of indoor air in a multistoried residentialbuilding of 81 flats built in 1960. The building is located in a heavily built urban area ofHelsinki. The building had a mechanical exhaust ventilation system without outdoor air inlets.A questionnaire was sent to occupants and a condition survey was made prior to renovation. Themain indoor climate problem was draught with a prevalence of 60 %. Other almost as commonproblems were traffic noise also during nights and dust coming from the street.

The emissions of building materials like volatile organic compounds and indoor airbornecontaminants such as environmental tobacco smoke expose occupants to hazardowsubstances. Although impacts of indoor air quality problems on human health, comfort, andproductivity are quite large, no adequate evaluation methodology exists to assess contaminantsource control techniques and building equipment systems.