tailieunhanh - Volatile Organic Compound Concentrations and Emission Rates Measured over One Year in a New Manufactured House

Temporal variations in indoor VOC concentrations in the house likely were affected by changes in the sources with age and in the house parameters, principally air change rate, temperature and relative humidity. Air change rates in the house, which was operated at a single defined condition for all the sampling periods, were affected by wind speed and temperature conditions. At low wind speed conditions (wind speed | LBNL-56272 Volatile Organic Compound Concentrations and Emission Rates Measured over One Year in a New Manufactured House Alfred T. Hodgson1 Steven J. Nabinger2 and Andrew K. Persily2 1 Indoor Environment Department Environmental Energy Technologies Division Lawrence Berkeley National Laboratory Berkeley CA 94720 USA National Institute of Standards and Technology Gaithersburg MD 20899 USA September 2004 Abstract A study to measure indoor concentrations and emission rates of volatile organic compounds VOCs including formaldehyde was conducted in a new unoccupied manufactured house installed at the National Institute of Standards and Technology NIST campus. The house was instrumented to continuously monitor indoor temperature and relative humidity heating and air conditioning system operation and outdoor weather. It also was equipped with an automated tracer gas injection and detection system to estimate air change rates every 2 h. Another automated system measured indoor concentrations of total VOCs with a flame ionization detector every 30 min. Active samples for the analysis of VOCs and aldehydes were collected indoors and outdoors on 12 occasions from August 2002 through September 2003. Individual VOCs were quantified by thermal desorption to a gas chromatograph with a mass spectrometer detector GC MS . Formaldehyde and acetaldehyde were quantified by high performance liquid chromatography HPLC . Weather conditions changed substantially across the twelve active sampling periods. Outdoor temperatures ranged from 7 C to 36 oC. House air change rates ranged from h-1 to h-1. Indoor temperature was relatively constant at 20 C to 24 oC for all but one sampling event. Indoor relative humidity RH ranged from 21 to 70 . Tel. 1-510-486-5301. E-Mail ATHodgson@ The predominant and persistent indoor VOCs included aldehydes . formaldehyde acetaldehyde pentanal hexanal and nonanal and terpene hydrocarbons . a-pinene 3-carene and d-limonene which are .

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