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The study was carried out on 6 subjects. Each one is seated at a desk with a mounted PVS. During the experiment the room air temperature was controlled at 28C and the personalized air temperature was 25C. Several fluctuations were tested, air movement with a frequency of 0.2 Hz was preferred to 0.1 Hz and 0.3 HZThe subjects had a preference for a lower mean air velocity but were more distracted when air movement fluctuated (0,2 Hz) than when it was constant.

The authors introduce a new airflow characteristic, the equivalent frequency, as an integral measure for the frequency of the random velocity fluctuations in rooms. The aim of that study was to test the impact of the equivalent frequency on draught sensation for human subjects. Further investigation at different air temperatures along with different turbulence intensities of air velocity is recommended.

CFD is used to simulate the effects of respiration in displacement ventilated rooms. It was done in a satisfactory manner.An extra simulation was carried out with "density-corrected" exhalation temperature, to see if the results are sensitive to variations of this parameter. This proved not to be the case. The choice of the flow rate is more important for the flow pattern.

16 segmental and all body heat transfer convective coefficients were determined in tests performed with a thermal mannequin placed in the test chamber of a large wind-tunnel.This paper presents a general table with the numerical coefficients of the equations representing the evolution of the convective coefficient with the flow velocity for all the studied cases (front, back and side flow - at seated and standing postures) . The effect of natural convection is more obvious on the central part of the body. Peripheric parts have stronger losses.

Indoor air cleaners are available on the market but a lot of them are not tested and their performances are not known. The main objective of our study was to develop a laboratory test method which allows to determine the life span of indoor air cleaners. Loading of the device is carried out with tobacco smoke which is an air pollutant that reflects real conditions. Fractional efficiency and air flow rate of the device are measured at the initial stage (clean device) and step by step as the device becomes loaded.

The National Institute for Occupational Safety and Health (NIOSH) has undertaken a long-term performance test of heating, ventilation, and air-conditioning (HVAC) system filters. This testing is being conducted at the NIOSH facility in Morgantown, WV in an air handling unit (AHU) that services the animal quarters. The six-pocket bag filters in this AHU have been replaced with higher efficiency mini-pleat V-Bank filters and have been monitored monthly for filtration efficiency.

Air quality begins with good engineering air handling system (HVAC) controls. Air handler filters should remove the major particulate matter from incoming ambient air. A study of various NIOSH air handler bag filters was conducted to determine their filter efficiency against submicrometer particles (0.03-0.4 micrometers), since submicrometer particles are the most penetrating. Aerosol penetration measurements show an extremely large range of filter efficiency.

Several indoor air biofilters containing higher plants, mosses and microbes have been incorporated into functional offices, where they are a supplemental means of controlling indoor air quality through the removal of volatile organic compounds. In theory a rich microbial community indoors may in fact lower air quality through the production of microbial agents such as spores or aerial bacteria. Questions have arisen regarding the impact of an indoor air biofilter on ambient spore concentrations including the pathogen Legionella pneumophilia.

In buildings with mechanical ventilation, particles accumulate in the supply air filters. We conducted a field experiment in a school to investigate if such pollutants could affect the health of the pupils. In a school building we changed old and new supply air filters in the air handling units, with a cross over design of the study. Pupils answered a symptom questionnaire, and a subset of pupils was also examined by objective clinical methods.

Maintenance workers expressed concern of a potential health hazard due to a strong odor from used ventilation filters during routine maintenance at a research facility. This prompted a thorough examination of the physical and chemical nature of the filters and collected particulate matter. Light and electron microscopy indicated a predominance of opaque small particles, mostly in the submicrometer range. Many were agglomerations of smaller, roughly spherical subunits, consistent with combustion aerosol.