English

The study used CFD to examine reactions between ozone and terpenes in a room under 4 conditions. The study indicates that chemical reactions can significantly alter the concentration of air pollutants, an imperfect mixing may result in reactant and product concentrations significantly different from those predicted by the model that assumes fully mixed conditions.

When using RANS turbulence models the mean profiles of mixed convection can be predicted with accuracy. It is more important to resolve large scale 3D structures instead of using very complex turbulence models, for the prediction of room airflow with floor heating or cooled ceiling.

This study consisted first in a sampling campaign that has shown the important levels of NCL3 encountered in swimming pools. Then a simulation of the NCL3 dispersion was conducted wtih the following simulation tools : TRNSYS (thermal simulation) and FLUENT (CFD simulation).

The methods for estimating or calculating the noise reduction in ductwork are described. Information is given about noise propagation in straight circular or rectangular ducts and in ducts with diameters changes, bends, elbows or junctions. Noise reduction by air diffusers, filters, coils, is also presented, as well as noise emission by ducts walls.

The article summarizes the results of three recent Danish studies showing that the improvement of air quality in offices increases productivity by 5% or more. It also mentions a recent Danish study about the annual benefit of improved air quality, which was found as being at least ten times higher than the increase in costs.

Ventilation strategies for multiunit residential buildings are described according to the results of a survey in 260 randomly selected buildings in Canada. Most buildings use corridor pressurization systems with an either central or apartment-based air exhaust. Some outdoor air is delivered to individual apartments, but in some cases, corridor air systems act as a ventilation system for individual apartments. Occupants complaints have been recorded, the main one being odor transfer between apartments.

This article presents the new requirements of the ANSI/ASHRAE standard 62-2001, Ventilation for Acceptable Indoor Air Quality, including recent changes of the standard available at the Ashrae web site. It explains the status of the 31 addenda to the 1999 version of the standard, some of them being included in the 2001 version, others being still in discussion or in the process to be adopted.

This method enables the determination of the influence of heating source characteristics on mean radiant temperature for composite room surfaces, as well as on thermal comfort and discomfort. A maximal possible thermal comfort area can be achieved with the determination of the best interactive influence between the building structure and its heating system.

The objective of this parametric study is to vary some parameters related to the conception of an atrium in order to analyse through CFD calculations their impact on the thermal behaviour during the critical summer conditions. The guideline produced are intended to help the architects especially at the first stage of the conception process.

The results of a study testing the possibility of using Dynamical Thermal Modelling (DTM) techniques within CFD are reported in this paper. Two test procedures (an extensive one and a simplified one) were conducted for the modelling of an enclosure, to model heat exchanges through building materials and effects on internal temperatures and air flows.