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Green Building Research Lab News

Updates on GBRL Activities

January 23, 2017

The GBRL recently hosted a group of prospective undergraduate engineering students who were interested in learning more about thermal fluid science research at Portland State University. The students toured the Green Building Research Lab and saw demos about ongoing research on pollutant deposition on building material surfaces, volatile organic compound analysis with PTR-TOF-MS, how to measure turbulent flows, and our team's progress in building Arduino-based air quality sensors. Thanks to the great undergraduate and graduate students in the GBRL who made this tour happen. A few pictures from the event are below:


Pradeep R., graduate student in the GBRL discusses the operation of a sonic anemometer - soon to be deployed to an ecoroof field site.


GBRL Undergraduate researcher, Craig L., discusses the role of Arduino in building science and air quality


Mimi S., undergraduate researcher in the GBRL, shows a prospective student progress on her 'low-ish cost' Arduino air quality sensor. These sensors will soon be field calibrated and deployed at a field site with a vegetated ecoroof to understand spatial variability in air pollution levels across a rooftop. 


December 12th, 2016

The GBRL has received delivery of a proton transfer reaction-time of flight-mass spectrometer! This is a state of the art instrument for measuring volatile organic compounds in real-time and at as low as parts per trillion levels. The GBRL will apply this technique to several important domains of air quality and building science research, including human VOC emissions and interactions, indoor heterogeneous chemistry, and urban surface-atmosphere exchange processes. Check out the pictures from the install and training late last week:


November 8th, 2016

GBRL research is in the spotlight at GBRL Director Elliott Gall was interviewed for an article concerning ventilation rates, indoor air quality, and health. In the article, Dr. Gall discusses a recent publication that measured CO2 exposure in a cohort of subjects in Singapore, as well as work investigating the effectiveness of CO2 sorbents. A relevant excerpt about Dr. Gall's study of CO2 exposure from the article is below, and the full article can be found at Building Green (or click the photo below from the article)

Another study conducted in Singapore tracked CO2 exposure levels by attaching sensors to 16 individuals and observing exposure levels throughout a period of one week. Nearly all participants spent at least an hour of a typical day with CO2 elevated over 1,100 ppm. In this study, it turned out that a major determinant of more exposure was the mode of bedroom ventilation; people who used air conditioning units in their bedrooms instead of natural ventilation had many more instances of exposures to high CO2 levels and were also the only group that experienced CO2 levels over 2,500 ppm. For everyone in the study, the vast majority of significant exposure events—where CO2 levels fell between 1,000 ppm and 2,500 ppm for 2.5 hours or more—occurred in the home, whereas only 9% of those events occurred in an office.

“We have to understand the places where these exposure events occur,” Elliott Gall, Ph.D., lead author on the paper, told BuildingGreen. “Most studies are focusing on mimicking office environments, when what we found was that residences can be much worse.” While that was just one small study done in Singapore, other studies corroborate that offices tend to not have as much trouble with elevated CO2 levels (though problems are common in meeting or conference rooms with high occupancy levels); in a 2008 survey of 100 U.S. offices, only 5% of the measured peak indoor CO2 concentrations exceeded 1,000 ppm.

November 2, 2016

Dr. Gall was the most cited ResearchGate researcher in the MME department for the month of October! 

October 25th, 2016

GBRL researcher and Ph.D. Candidate Omed Abbass (in collaboration with David Sailor and Elliott Gall) received word that the article entitled "Effect of fiber material on ozone removal and carbonyl production from indoor carpets" was accepted to Atmospheric Environment. Congrats, Omed! This article looked at six types of carpets with varying pile type (the fibrous part that you step on) for uptake of ozone and, importantly, what byproducts result from that interaction with ozone. Carpets are an important indoor material due to their high coverage area in many indoor environrments; they also generally exhibit a fairly strong pathway for ozone removal and often form oxygenated VOCs which emit into the indoor environment as secondary emissions. 

Find more here:

October 20th, 2016

The Gall Research Group received word the paper entitled "Investigating CO2 removal by Ca- and Mg- based sorbents with application to indoor air treatment" was accepted to the journal Building and Environment this week. This paper looked at four sorbents and extensively characterized physico-chemical properties related to their capacity to remove indoor CO2, with particular focus on shelter in place facilities which are characterized by very small volume (5-10 cubic meters), high occupant density, (2-4 people in that small volume) and very low ventilation rates. These conditions are essentially worst case for exposrues to CO2 - modeling shows levels may quickly reach in excess of 10,000 ppm, where acute health effects may be of concern. The modeling suggests low cost sorbents may be effective in shelter in place conditions when indoor-outdoor air exchange may be limited due to adverse outdoor conditions (e.g., hazardous air quality due to chemical release). 

Access if free for the next 50 days here:

September 9th, 2016 

GBRL Director Elliott Gall and Ph.D. Candidate Omed Abbass presented an overview of GBRL capabilities at the 2016 Oregon BestFEST in downtown Portland. A great opportunity to see the work being done at other OregonBEST funded laboratories. The conference highlighted the activity of startups in the Northwest, with several compelling "pitches" given by startups in the building sciences arena, including a startup focused on 'energy efficiency as a service' and a startup looking to improve building automation in multifamily dwellings. Great stuff. 

September 2nd, 2016


GBRL Director Elliott Gall and GBRL Undergraduate Researcher Dreonna Johnson at the REU Symposium

GBRL Undergraduate Researcher Dreonna Johnson presented the findings of her summer research experience as part of the PSU Center for Climate and Aerosol Research NSF REU program. Her project was titled: Development of a low cost platform for personal, real-time monitoring of activity and exposures to multiple air pollutants. She made several excellent presentations at the symposium: a poster presentation and a 7-minute "flash" presentation highlighting the results of her study. Dreonna's work combined several off-the-shelf sensors that she assembled into a "personal monitoring kit" that enabled real-time monitoring of personal levels of CO2 (carbon dioxide), CO (carbon monoxide), TVOC (total volatile organic compounds), and PM (particle concentrations). In addition, she collected a unique dataset of quantitiative metrics of activity, including accelerometer data, GPS location, speed, and step count. Analysis continues on this dataset, but preliminary findings show correlations between CO2 and TVOC in certain indoor locations (but not all) as well as transient, elevated levels of pollutants during specific activities. For example, one subject involved in the study had personal TVOC levels elevated by ~3 orders of magnitude when blow drying her hair. 

Dreonna will return to UCLA to complete her undergraduate studies - best of luck! 


August 10th, 2016

Funding was granted by the National Science Foundation (NSF) in 2016 to investigate the effects of ecoroofs on indoor air quality. Research goals respond to two key questions: 1) How does the design of a building rooftop affect deposition, processing, and emissions of air pollutants? and 2) How might ecoroofs affect indoor air quality? This project will address these questions with a combination of techniques that integrate ecology, biology, and building science approaches. Specific investigations will include a broad field survey of 48 roof surfaces in Portland, OR, an intensive air quality monitoring study at a commercial facility with a dual ecoroof/white membrane roof, and bench-scale laboratory investigations. Field measurements and laboratory parameterizations will be used in statistical models and material balances to explain relationships between the urban environment, ecoroofs, and indoor air quality.