English

Airborne particle size distribution depends on the type of source from which the particles originate - filtration efficiency in turn, is dependent on particle size. Thus, in order to optimise filtration efficiency, it is important to gain knowledge on both: the size distribution of particles in the air to be filtered and the relationship between filtration efficiency and particle size. In addition, assessment needs to be made about the expected concentration level of particles around the building envelope and its time variation.

Reactions among pollutants in the intake air can increase the concentrations of irritating and hazardous products in the indoor air and may lead to an increase of the sick building syn-drome (SBS). A short description of an experimental set-up that enables the studies of the impact of different settings of a full scale ventilation system on air with different ambient compositions is presented. Preliminary sampling using Tenax TA show that some reaction rates are increased in the experimental set-up, which could indicate that heterogenous reactions occur.

Particle number concentrations and size distributions were measured in the living room of an unoccupied apartment located in a street canyon in central Copenhagen, in the street, and at a nearby urban background station. A simple dispersion model was used to calculate the particle concentrations outside a window facing the street from where most of the ventilation air was supplied. The penetration efficiencies and the deposition rates were estimated using the concentration rate balance, ignoring indoor sources.

Accurate characterization of particle concentrations indoors is critical to exposure assessments. It is estimated that indoor particle concentrations depend strongly on outdoor concentrations. For health scientists, knowledge of the factors that control the relationship of indoor particle concentrations to outdoor levels is particularly important. In this paper, we identify and evaluate sources of data for those factors that affect the transport to and concentration of outdoor particles indoors.

Irritative and respiratory symptoms are reported from people working or living in damp and mouldy buildings, but signs of pulmonary involvement have not yet been found. We studied 522 teachers working in 15 primary schools with various degrees of dampness and mould growth. Symptoms, spirometry, CO-diffusion, and bronchial challenge was compared to classification of dampness and mould growth in or outside classrooms.

Authors assessed building-related risk factors for lower respiratory symptoms in office workers. The National Institute for Occupational Safety and Health in 1993 collected data during indoor environmental health investigations of workplaces. Multivariate logistic regression analyses were used to assess relationships between lower respiratory symptoms in office workers and risk factors plausibly related to microbiologic contamination.

Computed tomography consists in measuring chemical concentrations profiles in a room from the attenuation of a large number of laser rays and converting measurements in a two dimensional concentration profile by a reconstruction algorithm. This study shows the effectiveness of one of these algorithms (Low Third Derivative).

In order to identify the complex flow located at the breathing zone of a seated person exposed to the airflow coming form a PVS (personalized ventilation system) two techniques are used and compared : the PIV ( a two-dimensional particle image velocimeter) and the LDA (laser doppler anemometer) technique with a single point measurement, given by a cross section of laser beams.
The PIV technique appears a very interesting tool in studies aiming at identifying airflow in rooms or around objects.

A new type of thermal manikin DRESSMANN (Dummy Representing Suit for Simulation of huMAN heatloss). is presented : it consists of an overall, that can be worn by a person or a manikin, on which up to 32 heated sensors (artificial skins) can be fixed everywhere by velcrose fastening.
DRESSMANN presents the advantages of heated dummies and of small sensors . It can be used in buildings, vehicles, planes or trains.

For that study , an heated manikin, in a seated position, is exposed to a local thermo ventilator that promotes a non-uniform horizontal flow ( front , behind and right side) ; an interior climate analyser measures the environmental variables around the manikin. Those data are used as inputs of the numerical program.
A numerical model simulates the human and clothing thermal systems and evaluates the thermal comfort level. Verification was made that when the ventilator is places in front of the manikin, acceptable thermal comfort conditions are fullfilled.