The building envelope as an air filter.

Recent research suggests that fine-particulate air pollution increases the incidence of lung disease and premature death. In this paper, single fibre filter theory was used to predict the theoretical particulate collection efficiency of air permeable walls (dynamic insulation). The relationship between particle diameter and filtration efficiency for dynamic insulation, as a function of flow rate, is examined and compared to that for a conventional filter.

Relating sick building symptoms to environmental conditions and worker characteristics.

Recent concern has centered on "sick buildings" in which there has been an unusually high percentage of health complaints by the building's occupants. Typically, these symptoms are thought to be tied to indoor air quality characteristics, such as high levels of respirable particles or volatiles, thermal conditions, etc. In addition, recent studies have drawn connections between "sick building syndrome" (SBS) symptoms and non-environmental variables, i.e., personal and occupational factors. This paper presents a brief review of a study by Hedge et al.

Developments in noise control.

Unless requirements are laid out in codes, control of noise in buildings is often an afterthought. The measures taken to control noise, however, are invariably linked to other building subsystems. Mechanical and plumbing subsystems generate noise; the design of walls, ceilings and floors affects sound transmission.

This paper addresses four topics:

Impact of early stage incomplete mixing on estimating VOC emissions in small test chambers.

Most of the existing emission models developed from small-scale chamber tests assume complete mixing in the chamber throughout the test period. This paper examined this assumption using a Computational Fluid Dynamics (CPD) model. The model simulated the three-dimensional air velocity profiles and Volatile Organic Compound (VOC) concentration distributions from wood stain in a well-designed mixing chamber of 1.0X0.8X0.5 m3. The model used measured data to determine the time-dependent voc surface concentrations of wood stain.

Candle in the wind.

      

Building for better breathing.

              

Impact of temperature and humidity on the perception of indoor air quality.

Sensory responses to clean air and air polluted by five building materials under different combinations of temperature and humidity in the ranges 18-28°C and 30-70%RH were studied in the laboratory. A specially designed test system was built and a set of experiments was designed to observe separately the impact of temperature and humidity on the perception of air quality/odor intensity, and on the emission of pollutants from the materials. This paper reports on the impact on perception.

Natural ventilation and automation with manual overriding are health solution.

The need for individual control with manual overriding combined with controlled natural ventilation is discussed. It is made plausible that with these two facilities problems related with the Sick Building Syndrome can be avoided. This principle is applied in a so-call led passive climate system. A system is devised setting the level of heating and ventilation by controlling motors fitted to radiators, ventilation openings in windows, Venetian blinds and outside shading. Moreover, it will switch on the lighting when natural lighting is inadequate.

A study of a control strategy utilizing outdoor air to reduce the wintertime carbon dioxide levels in a typical Taiwanese bedroom.

A C02 concentration of more than 1000 ppm has been monitored in Taiwanese bedrooms during sleeping hours in the wintertime. The high indoor C02 levels were caused by poor ventilation due to insufficient ventilation rates. This study sought to reduce the wintertime C02 concentration level in a typical Taiwanese bedroom with less outdoor air to maintain thermal comfort. C02 was used as an indicator to assess whether an adequate ventilation rate has been obtained to dilute or remove harmful pollutants.

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