Brookhaven air infiltration measurement system (BNL/AIMS) description and application

Abstract

iSTICE pOBTtins OF mm HEPSIT ABE iiitiieit. it has beei reprciaced from the test awallaMe copf to permit the broadest possible availability.

Evaluation of the perfluorocarbon tracer technique for determining infiltration rates in residences

“…The average PFT source strengths were adjusted to the 23 °C base temperature at which the experiments took place according to the following formula (15): S't = S'25e-400°d/r-i/298) (6) where S\ = PFT source strength at the average base temperature (t, °C) in nL/h, S 25 = PFT source strength at 25 °C (determined gravimetrically as 5688 ± 120 nL/h), and T = average base temperature (t, °C) in kelvin at which the PFT source is used. For short-term (less than 48 h) temperature changes, the exponential constant was found to be half that for long-term (greater than 10 days) changes (15). Thus, when the temperature of the chamber was varied for short-term changes S't = S'2Be-ß / -, ßß) (7) where S't = PFT source strength at chamber temperatures in nL/h, S23 = PFT source strength at 23 °C base temperature (from eq 6) in nL/h, and T = chamber temperature in K.…”

“…One steady-state tracer gas method for assessing airexchange rates, developed at Brookhaven National Laboratory and called the Brookhaven National Laboratory Air Infiltration Measurement System (BNL/AIMS) (10), is being extensively employed in large field studies of indoor air quality and impact of weatherization (11)(12)(13)(14). The BNL/AIMS method consists of miniature perfluorocarbon tracer (PFT) sources and miniature passive capillary ad-0013-936X/85/09 19-1225$01.50/0 © 1985 American Chemical Society Environ.…”

“…The PFT sources emit the tracer gas at a constant rate for 2-7 years. The emission rate, however, does vary with temperature (15). The emission rates are determined gravimetrically.…”

“…Use of a programmable sampler with sampling pump will allow for multiple short-term (<1 h) sample collections for determinations of air exchange rates on a short-term basis. The small size of the sources and samplers, their passive nature (e.g., no pumps), wide range of sampling times (from hours to weeks or months), ease of analysis, and relative low cost have made the BNL/AIMS ideally suited to large-scale field studies of infiltration rates in residences and large buildings (16).…”

A Strategy for International Energy Agency Ventilation and Indoor Air Quality Research

“…Ideally, this needs to be based on ventilation measurement techniques suitable for largescale implementation in occupied buildings. An appro priate technique is the passive tracer gas method, devel-oped by Dietz et al [2], which enables inexpensive mea surements to be made in occupied buildings over extended periods. Most importantly, this method measures the total air change rate, including that resulting from window opening and other occupancy actions.…”