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Alevantis L.,Indoor Air Quality Section | Levin H.,Building Ecology Research Group
ASHRAE Journal | Year: 2011

A great deal of attention has been given to the selection of building materials for enhanced indoor air quality (IAQ) in several green building rating systems and standards. Some limited recent research has shown good correlation between perceived IAQ and measured concentration levels of chemicals associated with the odors. The research has found that it is important to recognize that an emissions label or a lab certificate reflects only the test conditions and chemicals it represents, it may or may not result in a healthy environment for all occupants. Materials that are not readily damaged by water are also desirable to avoid rapid deterioration and the need for replacement or to avoid mold growth and other impacts associates with wet materials. Standard 180-2008 is a good guidance document for general HVAC maintenance, while Standards 62.1-2010 and 189.1-2009 should be consulted for specific IAQ-related maintenance tasks.

Chen W.,Indoor Air Quality Section | Persily A.K.,U.S. National Institute of Standards and Technology | Offermann F.J.,Indoor Environmental Engineering | Poppendieck D.,U.S. National Institute of Standards and Technology | Kumagai K.,Indoor Air Quality Section
Building and Environment | Year: 2014

Product loading ratio and area-specific airflow rate are among the key parameters required for indoor air quality (IAQ) modeling and exposure health assessment of building product emissions. This paper analyzes product loading ratio variations and generates area-specific airflow rate distributions of major categories of interior building products for single family detached (SFD) homes in the U.S. The product categories addressed include ceiling, flooring, interior wallboard & paint, walls & wall coverings, doors, insulation and window treatments. The analysis employs a set of 83 SFD homes that are defined by Persily etal. (2006) as representing 80% of U.S. housing stock built prior to 1998. We first calculate product loading ratios from floor plans of these homes. We then combine the loading ratios with the air change rates previously modeled using CONTAM by Persily etal. (2010) to develop a national, average area-specific airflow rate distribution for each product category. We further analyze the trends affecting area-specific airflow rate distributions in newer homes. Finally, we discuss the implications of these results on assessing IAQ impacts of building products, especially their application to improve product standards for volatile organic compound (VOC) emission testing and evaluation. © 2013 .

Sidheswaran M.,Lawrence Berkeley National Laboratory | Chen W.,Indoor Air Quality Section | Chang A.,Indoor Air Quality Section | Chang A.,University of California at Berkeley | And 6 more authors.
Environmental Science and Technology | Year: 2013

Formaldehyde emissions from fiberglass and polyester filters used in building heating, ventilation, and air conditioning (HVAC) systems were measured in bench-scale tests using 10 and 17 cm2 coupons over 24 to 720 h periods. Experiments were performed at room temperature and four different relative humidity settings (20, 50, 65, and 80% RH). Two different air flow velocities across the filters were explored: 0.013 and 0.5 m/s. Fiberglass filters emitted between 20 and 1000 times more formaldehyde than polyester filters under similar RH and airflow conditions. Emissions increased markedly with increasing humidity, up to 10 mg/h-m2 at 80% RH. Formaldehyde emissions from fiberglass filters coated with tackifiers (impaction oils) were lower than those from uncoated fiberglass media, suggesting that hydrolysis of other polymeric constituents of the filter matrix, such as adhesives or binders was likely the main formaldehyde source. These laboratory results were further validated by performing a small field study in an unoccupied office. At 80% RH, indoor formaldehyde concentrations increased by 48-64%, from 9-12 μg/m 3 to 12-20 μg/m3, when synthetic filters were replaced with fiberglass filtration media in the HVAC units. Better understanding of the reaction mechanisms and assessing their overall contributions to indoor formaldehyde levels will allow for efficient control of this pollution source. © 2013 American Chemical Society.

Mendell M.J.,Indoor Air Quality Section | Mendell M.J.,Lawrence Berkeley National Laboratory | Macher J.M.,Indoor Air Quality Section | Chen W.,Indoor Air Quality Section | Kumagai K.,Indoor Air Quality Section
Indoor Air 2014 - 13th International Conference on Indoor Air Quality and Climate | Year: 2014

While current evidence suggests that prevention and remediation of indoor dampness and dampness-related agents are likely to reduce health risks, evidence is not yet available to support quantitative guideline levels for specific indoor microbiologic concentrations. This paper recommends approaches for developing evidence to support quantitative health-protective guidelines for indoor dampness and dampness-related agents. These approaches include better assessment of environmental factors related to health effects, for factors ranging from crude indicators like visible water damage or mold odor, to slightly more quantitative metrics for measured material moisture levels, to highly quantitative microbial assays. Example research strategies are described for measured indoor moisture and health effects.

Mendell M.J.,Indoor Air Quality Section | Mendell M.J.,Lawrence Berkeley National Laboratory | Macher J.M.,Indoor Air Quality Section | Kumagai K.,Indoor Air Quality Section
Indoor Air 2014 - 13th International Conference on Indoor Air Quality and Climate | Year: 2014

In developing evidence-based, health-protective guidelines for indoor dampness/mold, one goal is to quantify the health risks from indoor dampness. A first step is to synthesize existing epidemiologic findings on measured home moisture and health. Findings were combined from the only two published studies assessing associations between measured wall moisture and health. Both studies used the same make of two-pin, electronic resistance-type moisture meter on gypsum plaster-on-brick walls in UK homes. Both showed dose-related increases in asthma exacerbation with higher measured moisture, in one study beginning at 10-15% wood moisture equivalent (%WME) and reaching an odds ratio of 7.0. Further research is needed to extend this relationship to include measured "water activity" (Aw, a scale assessing moisture availability directly relevant to microbial growth), other types of moisture meters, and other building materials. Such assessments will be useful until acceptable levels of identified dampness-related causal agents are determined. Meanwhile, evidence-based, health protective, quantitative guidelines for building-related dampness would have great utility.

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