A method to measure the ozone penetration factor in residences under infiltration conditions: application in a multifamily apartment unit

Abstract

Recent experiments have demonstrated that outdoor ozone reacts with materials inside residential building enclosures, potentially reducing indoor exposures to ozone or altering ozone reaction byproducts. However, test methods to measure ozone penetration factors in residences (P) remain limited. We developed a method to measure ozone penetration factors in residences under infiltration conditions and applied it in an unoccupied apartment unit. Twenty-four repeated measurements were made, and results were explored to (i) evaluate the accuracy and repeatability of the new procedure using multiple solution methods, (ii) compare results from 'interference-free' and conventional UV absorbance ozone monitors, and (iii) compare results against those from a previously published test method requiring artificial depressurization. The mean (±s.d.) estimate of P was 0.54 ± 0.10 across a wide range of conditions using the new method with an interference-free monitor; the conventional monitor was unable to yield meaningful results due to relatively high limits of detection. Estimates of P were not clearly influenced by any indoor or outdoor environmental conditions or changes in indoor decay rate constants. This work represents the first known measurements of ozone penetration factors in a residential building operating under natural infiltration conditions and provides a new method for widespread application in buildings.

Quantifying the size-resolved dynamics of indoor bioaerosol transport and control

“…Measurements were conducted from January 2015 to January 2016 in studioE (the Suite for Testing Urban Dwellings and their Indoor and Outdoor Environments), a ~150‐m 3 unoccupied apartment unit on the third floor of a graduate student dormitory on the campus of Illinois Institute of Technology in Chicago, IL (Figure ). Full details regarding this unit are described elsewhere . Briefly, there is a central 100% recirculating air‐handling unit that is connected to a rigid sheet metal ductwork installed within conditioned space, but it is not connected to any heating or cooling system.…”

“…Full details regarding this unit are described elsewhere. 53 Briefly, there is a central 100% recirculating air-handling unit that is connected to a rigid sheet metal ductwork installed within conditioned space, but it is not connected to any heating or cooling system. There is one 40 cm × 64 cm return These airflow rates correspond to recirculation rates ranging from 10.8 to 11.5 per h, which are 40-50% higher than the average seen in typical residential and light-commercial buildings (although not out of the realm of possibility for similar spaces).…”

Ozone in urban China: Impact on mortalities and approaches for establishing indoor guideline concentrations

“…In a follow‐up study by the same group, they developed a method to measure ozone penetration factors in residences under infiltration conditions and applied it in an unoccupied apartment unit. The mean (SD) estimate of p was 0.54 ± 0.10 across a wide range of conditions using the improved method . Given the greater similarity in building construction and materials between urban China and the latter study, as well as the improved method in the latter study, we have used 0.54 ± 0.10 as the penetration factor with windows closed, p closed , and 1.0 as the penetration factor with windows open, p open .…”

“…The mean (SD) estimate of p was 0.54 ± 0.10 across a wide range of conditions using the improved method. 34 Given the greater similarity in building construction and materials between urban China and the latter study, as well as the improved method in the latter study, we have used 0.54 ± 0.10 as the penetration factor with windows closed, p closed , and 1.0 as the penetration factor with windows open, p open . We used 3.4 ± 1.3 for k, the first-order rate constant for ozone deposition to indoor surfaces, which reflects ozone removal by both indoor surfaces and humans reported within buildings both in China 20,35 and elsewhere.…”

Field evaluations of newly available “interference-free” monitors for nitrogen dioxide and ozone at near-road and conventional National Ambient Air Quality Standards compliance sites

“…The recent tightening (U.S. Environmental Protection Agency [EPA], 2015a) of the ozone National Ambient Air Quality Standards (NAAQS) does not require upgrading compliance monitoring networks with recently approved "interference-free" Federal Reference Method (FRM) ozone (O 3 ) instruments such as the Teledyne Air Pollution Instrumentation (TAPI, San Diego, CA) T265 nitric oxide (NO) chemiluminescence (CL) O 3 monitor (EPA, 2016) or the Federal Equivalent Method (FEM) 2B Technologies,Inc. (2B,Boulder,CO), nitric oxide (NO)scrubbed 211 ultraviolet (UV; 254 nm) photometer (EPA, 2016) that would minimize the interference bias present in the conventional network metal oxide-scrubbed (e.g., copper oxide [CuO], manganese dioxide [MnO 2 ]) UV photometers presently deployed (Kleindienst et al, 1997;Spicer et al, 2010;Johnson et al, 2014;Zhao and Stephens, 2016). Although current EPA-allowed inlet heights above ground level (AGL) may range within 2-15 m, they cluster in the 3-6 m range, averaging 5.4 m for urban sites (EPA, 2015b) and 10 m AGL for rural EPA Clean Air Status and Trends Network (CASTNET) O 3 compliance sites.…”