English

The aim has been to determine ventilation rates and risk of moisture damage in three modernschools with passive stack ventilation. The users are supposed to control the ventilation byusing the lantern windows and the outdoor air is assumed to enter through an undergroundduct. The paper presents results, analysis and conclusions from the performed measurementsand calculations.The ventilation rates are sometimes low and vary with the use of the windows in the facadeand the lantern. It is, however, always possible to arrive at a sufficient ventilation rate.

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 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.

Heat recovery in ventilation systems for office buildings in cold climates is necessary for tworeasons:1. To obtain acceptable indoor thermal comfort by preheating of fresh air,2. To reduce ventilation energy lossThis paper describes a pilot system built in the laboratory of the Norwegian Building ResearchInstitute, NBI, based upon the concept of an advanced fan assisted natural ventilation systemwith heat recovery. The concept was developed by NBI.

A humidity controlled air flow terminal device works as a humidity sensor : its openingsurface varies according to relative humidity inside a room in order to match air flow rate topollution. These components are fouling up when used during several months.In a laboratory, an air flow with a high rate of particules is fouling up five identical air devicesin a few hours. Considering a constant relative humidity, the impacts on two devices aresimilar : it seems that artificial fouling tests can be reproduced.

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.

Until now, there is no widely accepted way to express any index for this purpose and takinginto account the large variety of possible pollutants. Things can be simplified is the aim is moreto compare different systems and strategies than to give an absolute value of quality.For the study of a pollutant source, the main important point for comparison is the pattern ofits production, whatever this pollutant is.

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.

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.