An analysis of recently published research results is provided, showing that if molds and the different compounds they produce can lead to some health effects (allergies, infections, potential toxicologic effects) when inhalated, these effects occur only for exposures at very high doses. The potential toxicity from indoor air exposures is therefore very low, which allows to consider the term 'toxic mold' as a misnomer.
This article presents how ventilation and air quality in smoking spaces are being treated by ANSI/ASHRAE standard 62, Ventilation for Acceptable Indoor Air Quality. Historical information is given about environmental tobacco smoke and ventilation requirements in the standard since its first issue in 1973. The status of the 31 addenda to the 1999 version of the standard, some of them being included in the 2001 version, others still being in discussion or in the process to be adopted, is explained. Among them are four smoking-related addenda : 62e, 62g, 62o and 62ag.
The article describes the different types of cold beams used to cool rooms from cold water. Passive cold beams mainly exchange through radiation and natural convection ; they include no fresh air introduction. Active cold beams are mainly based on forced convection, hot air from the room being induced by fresh air. Mix systems try to combine radiation and forced convection. Main characteristics and advantages of cold beams as well as system design rules are also briefly given.
Measurements of temperature and local heat flux were operated on a vertical surface, such as a window, equipped with louvers, such as those of a venetian blind, for different window temperatures, irradiation levels, louver to window spacings and louver angles. Results have been compared with calculations (see Airbase record # 14975). The comparison validates the numerical study.
This article presents the numerical study of the influence of louvers, such as those of a venetian blind, on heat transfer from an adjacent vertical surface, such as the indoor side of a window. The physical model used is described. Results show the influence on radiative and convective heat transfer, which were found as being of the same magnitude, of louver spacing, louver tip to window spacing, louver angle, window surface temperature and irradiation.
A zonal model has been nested within a multizone model to allow increased resolution in the prediction of local air flow velocities, temperature and concentration distributions between and within rooms. Simulations from the new program have been compared with measurements and results from other models.
The current design standard BS EN ISO 7730 is based upon the work of Fanger dated 1995, dealing with a steady-state human heat balance model that leads to a prediction of the sensation of human thermal comfort for a given set of thermal conditions. That model was then developed for "conventional" environments. But is the current standard still applicable to more sophisticated environments such as offices with chilled ceiling, in combination with displacement ventilation ? This paper presents findings from a study that sought to answer that question.
This paper presents a simplified system based on a new air supply opening model along with a numerical method to accelerate and simplify the convergence procedure of predicting air distribution in ventilated rooms. The new numerical method is called error pre-treatment method. It is simpler than multi-grid method and effective for SIMPLE algorithm commonly used for indoor airflow simulation.
The authors have developed a whole-field measuring technique that allows the visualization of air temperatures and airflow patterns over a large cross-section. For that measurement, an infrared camera and a measuring screen placed in the airflow are used. Thanks to that technique, real-time images within large areas can be recorded and transient events can be captured. The method was applied to a flow from a low-velocity diffuser in displacement ventilation.
Five air terminal devices (ATD) have been tested in a typical office workplace with a breathing thermal manikin. Tracer gas used to identify the amount of air inhaled and the amount of exhaled air re-inhaled. An index was used to assess the performance of ATD.