@article{918aa6f81bd348a5ababa1d348b4314b,
title = "Ozone removal efficiency and surface analysis of green and white roof HVAC filters",
abstract = "Heating, ventilation, and air-conditioning (HVAC) system filters from a commercial building were tested for their ability to remove ozone from intake air. Filters were taken from rooftop HVAC systems installed for two months: one located on a white membrane roof and the other on a vegetated green roof. One new, unused filter sample was tested as a reference. Samples from these filters were exposed to ozonated air streams at 40 and 120 ppb and relative humidity levels of 30% and 70%. Filter surfaces were analyzed with a scanning electron microscope to observe the structure and composition of the materials loaded on each filter before and after exposure to ozone. The results show that for all samples tested, the ozone removal efficiency decreases with continued O3 exposure. Removal efficiencies of 5–15% for white roof and unused filter samples, and 10–25% for green roof filter samples were observed after 5 h of exposure to O3. Filters taken from HVAC units located in the green roof area showed more ozone removal than unused filters or those taken from white membrane roof area. Unexpectedly, the unused filter samples had slightly higher ozone removal than the white roof filter. The data also show that the ozone removal percentage is higher when tested with 40 ppb ozone inlet concentration than at 120 ppb. SEM images show deposits of biotic material that are present on green roof samples, ostensibly explaining the greater ozone removal efficiency of filters from vegetated roofs.",
keywords = "Green roof, HVAC filters, Ozone, Ozone removal",
author = "Abbass, {Omed A.} and David Sailor and Gall, {Elliott T.}",
note = "Funding Information: The authors wish to acknowledge assistance from Don Mosely and Robin Morse of Walmart who provided access to the study site roof under support from a Walmart Realty Compliance Grant. The authors would also like to thank Wentai Luo, and Tom Bennett, of Portland State University for providing useful notes in the construction of the test rig, and Greg Baty for support in use of the electron microscope center. Omed Abbass acknowledges the support of a scholarship from the Higher Committee of Education Development in Iraq (HCED). Elliott Gall was supported by the National Science Foundation under Grant No. 1605843. This research was supported in part by Assistance Agreement No. 83575401 awarded by the U.S. Environmental Protection Agency. It has not been formally reviewed by EPA. The views expressed in this document are solely those of the authors and do not necessarily reflect those of the Agency. EPA does not endorse any products or commercial services mentioned in this publication. Funding Information: The authors wish to acknowledge assistance from Don Mosely and Robin Morse of Walmart who provided access to the study site roof under support from a Walmart Realty Compliance Grant . The authors would also like to thank Wentai Luo, and Tom Bennett, of Portland State University for providing useful notes in the construction of the test rig, and Greg Baty for support in use of the electron microscope center. Omed Abbass acknowledges the support of a scholarship from the Higher Committee of Education Development in Iraq (HCED) . Elliott Gall was supported by the National Science Foundation under Grant No. 1605843 . This research was supported in part by Assistance Agreement No. 83575401 awarded by the U.S. Environmental Protection Agency . It has not been formally reviewed by EPA. The views expressed in this document are solely those of the authors and do not necessarily reflect those of the Agency. EPA does not endorse any products or commercial services mentioned in this publication. Publisher Copyright: {\textcopyright} 2018 Elsevier Ltd",
year = "2018",
month = may,
day = "15",
doi = "10.1016/j.buildenv.2018.03.042",
language = "English (US)",
volume = "136",
pages = "118--127",
journal = "Building and Environment",
issn = "0360-1323",
publisher = "Elsevier BV",
}