One of the major means of air diffusion for air conditioning equipment is the displacement ventilation. The stack effect is used by introducing at a very low speed, in the lower part of the room, some air whose temperature is close to the one of the desired atmosphere.
This paper proposes a space zone model for the calculation of all the airflow parameters based on tracer gas measurements, including flow rates of outdoor air, VAV supply. This approach gives a practical protocol for buildings managers to evaluate the performance of airside systems and determine air-conditioning and ventilation system performance parameters within acceptable errors.
This paper intends to resolve the spatial and temporal variation of VOC concentrations in apartments. Numerous indoor and outdoor measurements taken in the period between 1994 and 2001 have been analyzed.A method is presented, it can be used to normalize the results from VOC measurements taken at any time of the year. A table with adjustments factors is given.
This paper is a presentation of a methodology for developing responses to sudden releases of toxic pollutants in buildings. This methodology may be applied even if few data on the building are available.The results are several tools that describe uncertainty in the predictions and a model to rank the parameters depending to their influence on the expected reduction in model prediction uncertainties.
A questionnaire study (on ventilation, surface materials, heating and cooling) was performed on 3562 employees working in 32 buildings without previously known indoor air problems.The associations between symptom prevalence and building characteristics are reported in this paper.
Accurate mathematical models of airborne infection are needed to estimate the risk from secondary transmission of biological warfare agents. An equation has been derived by the authors : they determined the fraction of inhaled air that has been exhaled previously by someone in the building by using a CO2 concentration as a marker for exhaled-breath exposure.
There is a critical rebreathed fraction of indoor air below which airborne propagation of common respiratory infections and influenza will not occur.
Usually only primary emissions from building products are measured. That study takes into account potential secondary emissions due to oxidation with ozone. In the long run secondary emissions may influence the perceived air quality.The aim of that study was to investigate if the interaction between ozone and selected building products induces changes in emissions.
The RAGENA model of radon takes into account all the parameters and processes affecting radon levels (in the source, its transport, its entry into a dwelling and its accumulation indoors).The model has been tested in a mediterranean house. The results given by the model are similar to the ones obtained experimentally.
The aim of this study was to test the following hypthesis : in schools, bacterial markers may be increased in indoor air because of the presence of children.Dust samples were collected from the school rooms when occupied but also when unoccupied during the week-end. Results have been analysed and the conclusion is that in unoccupied rooms the airborne dust is of environmental origin, whereas the increase level of dust in occupied rooms is due to the children presence.
This study was carried out in nearly two hundred multi-family buildings, built before 1961, in Stockholm. Three thousand inhabitants answered first a questionnaire on symptoms and personal factors. In parallel energy saving measures and building characteristics were gathered. It appeared that major reconstruction of the interior were associated with an increase of some symptoms.