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.
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.
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.
Indoor air quality differences were investigated among five schools with and five schools without active humidity control systems. The active humidity systems provided approximately 15 cfm/person of ventilation air, while the schools without the active humidity control systems averaged less than five cfm/person. The space humidity levels in varying widely without active humidity control, and rose to unacceptable levels during summer shut-down periods.
Most single-family homes in America today are designed with a single-zone climate control system. This is typically an energy inefficient and ineffective method of conditioning a home. Multi-zone climate control systems are considered to provide improved means of conditioning single-family homes. More so is the case with multi-story homes where thermal balance is difficult to achieve between the lower and upper floors using a single-zone system.
The influence of inhabitants on indoor air quality (IAQ) was studied. The aim of the study was to find out how the inhabitants themselves and their living activities affect the IAQ. The concentration of volatile organic compounds (VOCs) and ammonia (NH3) in indoor air was measured in inhabited and in empty dwellings. A air change rates were also defined. Altogether 24 dwellings were examined. The results were compared with the surface floor area of the dwellings, the number of inhabitants, the number of pets and the absence or presence of smoking.
On March the 1st 2000 the Finnish Tobacco Act was amended, and now includes restrictions on smoking in restaurants and bars. Establishments can reserve a maximum of 50% of their service area for smokers, and the spreading of tobacco smoke into non-smoking areas must be prevented. In addition, the working areas at bar counters have to be smoke-free. 16 restaurants and bars participated in the study both before and after the introduction of the Finnish Tobacco Act.
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