Air Quality

From Living Building Science

About this subteam:


The Kendeda Building and its founders have made it their mission to provide its occupants and visitors with the highest standards of environmental health, yet little is known about the indoor and outdoor air quality. How the air quality index (AQI) surrounding and inside of the Kendeda Building compared to other spaces around campus is a vital in our research project. Particulate matter is a mixture of solid particles suspended in the air that consists of dust, smoke, and other organic and inorganic compounds. In order to understand the impact high levels of particulate matter has on people inside and outside the building, we need to have an idea of the current levels and future levels. Air quality has significant impacts on health and productivity of students, faculty, groundskeepers, Parking and Transportation (PTS) employees, and many others. Our findings will allow us to provide recommendations on improving campus air quality as we plan to partner with organizations such as the Student Government Association (SGA). Therefore, our research team aims to address indoor and outdoor air quality levels on Georgia Tech’s campus, specifically at the Kendeda Building and Clough Undergraduate Learning Commons.

The Living Building Standard

The Living Building Challenge for sustainable design requires that Kendeda meet requirements of seven performance areas or Petals: (1) Place, (2) Water, (3) Energy, (4) Health and Happiness, (5) Materials, (6) Equity, and (7) Beauty. The Energy, Health and Happiness, and Materials Petals address different efforts towards clean air in Kendeda's urban setting.

Energy Petal

The building is designed to reduce air infiltration and has operable windows that can be opened or closed depending on the outdoor temperature, humidity, and pollen count.

Health and Happiness Petal

The standard requires a Health Indoor Environment Plan which focuses on preventing and minimizing indoor pollutants. Some of its requirements include compliance with EPA's Safer Choice standard, materials that emit low levels of volatile organic compounds (VOCs), etc. It also utilizes a Dedicated Outdoor Air System (DOAS) which allows for a large amount of outdoor air to circulate through the building to occupants.

PurpleAir™ Monitor Network

Our network started off with four monitors back in Spring 2020 (2 at Clough and 2 at Kendeda). Now, we're proud to announce that our network encompasses 14 stationary monitors, both indoor and outdoor. Our network is now techically completed, although we may deploy an additional monitor in the coming semesters for investigating air quality in on-campus vs. off-campus student housing. This network spans all the way from Home Park and across campus to North Avenue Apartments. A map will be featured soon!

PurpleAir™ in Your Own Home: Our Starter Kit

To familiarize our newer members with the work that we've completed and the monitors that we use, we came together to create a starter kit full of resources on set up and use of a PurpleAir™ monitor in your own home. With this, we're hoping to encourage citizen science as more low-cost tools become available to take your personal air quality exposure into your own hands! This document details the most common things you need to know when owning and operating this device.

Air Quality Project [SPRING 2020]


The aim of this research is to investigate if there is a significant difference between indoor and outdoor air quality at the Kendeda Building, which abides by many stringent eco-friendly standards, and Clough, which is LEED (Leadership in Energy and Environmental Design) certified. Air quality has significant impacts on health and productivity of students, faculty, groundskeepers, Parking and Transportation (PTS) employees, and many others. Our findings will provide us with background and a basis to conduct future research so we have an idea of the general air quality trends in specific areas on campus. One of our goals is to provide campus organizations, such as the Student Government Association (SGA), with data and visuals to utilize when making decisions on campus environmental policies such as a move toward electric buses.

Research Question: How does indoor and outdoor air quality differ between the Kendeda Building and Clough Undergraduate Learning Commons as a result of particulate matter 2.5 (PM 2.5)?

Hypothesis: Indoor and outdoor air quality is more contaminated at the Kendeda Building than the Clough Undergraduate Learning Commons.

Figure 1: The picture shows our outdoor sensor location beside the Kendeda Building. We chose this location to compare the PM levels of the PurpleAir sensor with the Flow 2 portable monitor.​


We employed two kinds of sensors to collect particulate matter counts at various locations. We used two portable Flow sensors from Plume Labs to collect PM counts around campus. This included trolley rides, in dorms, and other areas on campus. For long-term collection of indoor and outdoor PM data at the Clough Undergraduate Learning Commons (CULC) and Kendeda Building, we employed four total PurpleAir sensors. The Kendeda and CULC each have an indoor and outdoor PurpleAir sensor installed. PurpleAir sensors primarily gather PM data, while the Flow sensors have the ability to gather data on PMs, VOCs, and nitrous oxides.

Data Analysis

We ran the PurpleAir data from April 5- April 17, 2020 through an Analysis of Variance (ANOVA) test along with Turkey-Kramer test.​ A p-value less than 0.05 is assumed to indicate statistical significance and rejection of the null hypothesis. The Turkey-Kramer test allows us to determine where the statistical difference is between the multiple sets of data . The Flow sensor and its GPS tracking data were filtered for PM 2.5 values greater than the EPA annual standard of 12 ug/m^3. The average latitudes and longitudes was then taken to provide a general idea of where the majority of campus emissions may be originating from.​


Overall, there was a significant difference in indoor and outdoor PM 2.5 levels at Kendeda and Clough. The ANOVA and Turkey-Kramer tests showed that there was a significant difference between each location. A p-value of approximately 0 was calculated for the indoor measurements at both locations while a p-value of 2.51*10^-19 was calculated for the outdoor measurements. These p-values indicate strong statistical significance and differences in the data sets. It was also observed that PM 2.5 levels spiked around April 5- April 8 and declined significantly after April 9 where levels stayed in the single digits.

Project Poster:

Air Quality Project [FALL 2020]

We were able to make initial conclusions for two research questions during the Fall 2020 semester.

1. How does the indoor air quality in Kendeda compare to air quality in other campus buildings?


We hypothesized that Kendeda had significantly better air quality compared to the other indoor buildings on our monitor network.


To investigate the standing of Kendeda's air quality compared to other indoor campus buildings, we decided to perform hypothesis t-tests to determine where each of five buildings stood in relation to Kendeda using PM 2.5 concentration data. We used the daily average PM2.5 concentrations (μg/m3) from November 1 to November 15 stored in an Excel file. Using MATLAB, we were able to load in PM2.5 concentration data to perform hypothesis t-testing.

Here are the hypotheses checked for the two-tailed t-test:

H0: The average PM2.5 concentration at the indoor monitor is not significantly different than the Kendeda indoor average.

H1: The average PM2.5 concentration at the indoor monitor is significantly different than the Kendeda indoor average.


The following is a table summarizing the conclusions of the hypothesis testing.

Indoor Monitor Difference from Kendeda Indoor
Clough Undergraduate Learning Commons No significant difference detected
Brittain Dining Hall Significantly higher
Home Park Kitchen Significantly higher
Campus Recreation Center Significantly higher
Boggs Building Significantly lower


This data in particular only represents a snapshot of time and place on campus, but it confirms the trends we have observed in our various interactions with the data thus far. At the very least, we can confirm that Kendeda has competitively healthy air quality in the scope of campus and pre-emptively with its low mean PM2.5.

The Home Park indoor monitor was installed so that we could consider student living in our picture of Georgia Tech's air quality. These young results already point us to notice that there is room for concern in student living. Moving forward, we would like to expand our network to include on-campus housing. This would provide us with a clearer picture of air quality for Georgia Tech students.

The dining halls also flag concern from this snapshot of data. In time, we could further investigate the reality of air quality in these campus facilities. From there, we could look into ways to improve air quality in student dining halls.

2. How did the COVID-19 shutdown impact campus particulate matter values? How did air quality change throughout campus reopening?


We hypothesized that decreased activity would decrease PM2.5 concentration averages during the shelter-in-place period in comparison to the long-term concentrations.


We decided to employ hypothesis t-testing to compare the PM2.5 concentrations from what data we have from the lockdown period to both the long-term and Spring-time data. We used the daily average PM2.5 concentrations (μg/m3) from April 5, 2020 to November 15, 2020 from each indoor/outdoor pair at Kendeda and the CULC. The lockdown period was evaluated at April 5 - April 30.

We also adjusted for seasonal variability and decided to compare the lockdown data to the Spring data (April 5 - June 20) instead. We adjusted the null hypothesis accordingly. The same results were echoed even when accounting for this seasonal variability.

Here are the hypotheses checked for the one-tailed t-tests:

H0: The monitor's PM2.5 concentrations recorded during the shelter-in-place period is not significantly lower than the long-term (or Spring) PM2.5 concentrations.

H1: The monitor's PM2.5 concentrations recorded during the shelter-in-place period is significantly lower than the long-term (or Spring) PM2.5 concentrations.


The Kendeda Indoor monitor is the only monitor which reported a detectable decrease in PM2.5 concentrations during the shelter-in-place period. No detectable decrease was recorded at the CULC indoor monitor, CULC outdoor monitor, or Kendeda indoor monitor. Both statements are true in when compared to the long-term and Spring-time concentrations.


Our hypothesis was largely incorrect. We could potentially attribute the decrease in Kendeda to minimal occupancy.

Next Steps

As a result of some of our findings and after discussing how to best move forward, we've decided on the following points of interest:

  • Recruiting a Computer Science (CS) major or someone who has prior coding experience
  • Resurrecting our idea to use our portable Flow air quality monitors to launch a pilot study using students from the VIP
  • Investigate relationships between air quality and student equity in off-campus and on-campus student housing
  • Work towards launching an automated campus air quality dashboard

Air Quality [SPRING 2021]

Dashboard Development

Steps Towards the Final Product

  • Main things we decided on to help guide the building of the dashboard: temperature and humidity graphs, an interactive map of the monitors, stats showing the highest readings on campus, daily averages for each monitor.
  • Held feedback sessions with various stakeholders and general student population to gain insight on what's most important to them and how to better help them understand the data they're looking at.
  • Had to do some coding on the backend of Tableau to create custom color schemes in line with EPA color standards for air quality and to fix the timezones and timestamps.
  • Worked with the library tableau data viz help desk to get the dashboard up on TableauPublic (free version of Tableau)
  • Data auto-updates every 24 hours by Tableau

Final Dashboard!/vizhome/GeorgiaTechAirQualityDashboard/LiveDashboard?publish=yes

Next Steps

  • Continue working with stakeholders to get dashboard displayed on screens in buildings
  • Update the timezone code calculation in Tableau to automatically account for Daylight Savings
  • Continue updating the aesthetics of the dashboard as we gather more feedback from users
    • Figure out feasible way in Tableau to display highest air quality reading stats/areas to avoid
  • Adapt dashboard to a phone-friendly version so people can view it better when scanning QR codes

Accuracy of Purple Air Sensors

  • As the dashboard is being made public, making sure the Purple Air sensors are displaying accurate data is fairly important
  • Meetings with Dr.Ng and Dr.Kaiser's group has led gave several insights to how Purple Air records data
  • Purple Air sensors have several drawbacks on thing is that it seems like Purple Air overestimates PM 2.5 consistently. This may be due to the fact that Purple Air extrapolates 2.5 from 1 according to Dr.Ng's research group
  • Atlanta in particular has an abundance of PM 1.0 particles, therefore if the PA sensors extrapolate using PM 1, it is going to overestimate.
  • The sensors on the outside mostly agree with each other with near 1 slopes and R squared values, which would imply that the sensors agree with each other
  • Therefore a correction factor can be added to each of the purple air sensors or individually to create more accurate data.

Folder with some graphs of sensor data:

Future Goals

  • Wait for more data in order to have better trends also as the campus will be more populated the graphs may change quite a bit
  • Figure out how to implement a correction factor to a live feed
  • Figure out how to deploy sensors to best record accurate and precise data.
  • It is also possible for sensors just to be faulty so also find the sensors that don't agree with others. This will be much harder inside and would basically would require two sensors to be in the same spot for a period of time.


We want to extend our gratitude to Dr. Cobb (EAS) and Dr. Clark (CS) for helping us in facilitating our work. We are also especially grateful for all of our partners who've helped us complete our air monitoring network and provided us with extremely helpful insight. None of this would have been possible without the support of our campus community.


Abbaszadeh, S., Zagreus, L., Lehrer, D., & Huizenga, C. (2006). Occupant satisfaction with indoor environmental quality in green buildings.​​

Fischer, Adam, "Quantitative Analysis of Traffic Related Air Pollution Along the Atlanta BeltLine East Side Trail." Thesis, Georgia State University, 2018.​

Peel, J. L., Metzger, K. B., Klein, M., Flanders, W. D., Mulholland, J. A., & Tolbert, P. E. (2007). Ambient air pollution and cardiovascular emergency department visits in potentially sensitive groups. American Journal of Epidemiology, 165(6), 625-633.​

Wargocki, P., Wyon, D. P., & Fanger, P. O. (2000). Productivity is affected by the air quality in offices. In Proceedings of Healthy Buildings (Vol. 1, No. 1, pp. 635-40).​​

Wu, X., Nethery, R. C., Sabath, B. N., Braun, D., Dominici, F. (2020). Exposure to air pollution and COVID-19 mortality in the United States. MedRxiv. doi:​

Team Members

Name Major Years Active
Caroline Miley Environmental Engineering 2020-Present
Madalene Henggeler Earth and Atmospheric Sciences, Mechanical Engineering 2020-Present
Camila Sanchez Environmental Engineering 2020-Present
Aaron Black Chemical Engineering 2021-Present
Ella Stewart Earth and Atmospheric Sciences 2020
Kaylyn Sinisgalli Environmental Engineering 2020
Nicole Romer Environmental Engineering 2020
Teisha Griffin Biology 2020