Rieke Elementary School
Rieke students spend the day in poorly ventilated classrooms
Unless air purifiers are run consistently
Like nearly all PPS schools, Rieke's HVAC system delivers low air-change rates in classrooms and other learning spaces. The district's own measurements show that Rieke does not meet health-based goals for ventilation. The best way to reach healthy air targets is with a combination of building ventilation and effective in-room filtration, but ventilation in Rieke is poor, and it is critical that Rieke receives ongoing support for placing and using in-room air purifiers.
The one air purifier originally assigned to Rieke‘s rooms is insufficient and undersized for Rieke classrooms and large spaces. Two or more air purifiers per classroom can substantially improve air quality, reduce respiratory viruses and air pollutants, and achieve effective air cleaning, while running at quiet settings.
Two air purifiers are needed in Rieke's classrooms, and library to more effectively clean the air. That’s why the Oregon Health Authority provided additional free air purifiers for Rieke in 2023. Rieke received enough additional units that each classroom should have two air purifiers each! Ensuring Rieke staff and families understand why they and their students benefit from running both units every day is important to classrooms meeting or approaching healthy air targets. To connect and support next steps for clean classroom air at Rieke, join our Rieke group, and learn more about Rieke‘s air quality below.
Without air purifiers, Rieke does not have clean indoor air
If no air purifiers are running:
✘ Coughs and sneezes in the typical Rieke classroom linger and hang in the air for over 1 hour 11 minutes
The median rate of airflow from the HVAC system to classrooms at Rieke is only 1.9 air changes per hour.*
At 1.9 air changes per hour, it takes the HVAC system 1 hour 11 minutes to clear out 90% of the respiratory aerosols being produced when kids and staff breathe, talk, sing, cough and sneeze. That is far too long for virus-laden respiratory aerosols and other indoor air pollutants to fill the air students and teachers are breathing.
But the median does not show how bad the lowest-ventilation rooms are …
✘ Classroom with the lowest ventilation: 8
0.1 air changes per hour
With airflow this low, how long do kids’ and staff’s viruses linger in room 8’s air?
>23 hours
At 0.1 air changes/hour, 23 hours is how long it takes the HVAC system to clear out 90% of respiratory aerosols and other air pollutants.
✘ Without air purifiers, 9 more Rieke classrooms have less than 2 air changes per hour
At 2 air changes per hour, it takes the HVAC system 1 hour and 9 minutes to clear 90% of the respiratory aerosols.
✘ 2 classrooms are between 2 and 3 air changes per hour & 6 more classrooms are between 3 and 6 – all below recommendations
Only 1 classroom meets our minimum health-based airflow target for the HVAC system alone of 6 air changes per hour or more, clearing 90% of aerosols out in 23 minutes or less.
Rm 22: 6.6***
***Good airflow:
Just 21 minutes to clear 90% of aerosols in room Rm 22
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About these ventilation measurements
These numbers come from airflow testing done in nearly every room of every PPS building, before the district resumed in-person learning in 2021. We carefully reviewed the district’s results, compiled and maintain a districtwide database from the airflow reports, and corrected gaps and errors in the data so that classroom ventilation and filtration are represented accurately. Our analyses provide ventilation rates from the HVAC system alone and show how total clean airflow increases when in-room air purifiers are used.
To learn more about the district airflow testing and how SIAFOS corrected the data, see this excerpt adapted from our McDaniel High School Air Quality Report: District airflow measurements & SIAFOS analyses. For the full room-by-room values, corrections, and calculations for this school, see Rieke Elementary School Analysis by SIAFOS.
One air purifier is undersized for Rieke classrooms
With only one air purifier per classroom, Rieke classrooms still lack clean air:
Although the Intellipure air purifiers originally assigned to Rieke improve the school's clean airflow rates, they are insufficient in Rieke classrooms. Even with an Intellipure air purifier running at its reasonable noise level (half speed), the classroom with the lowest ventilation from the HVAC system — room 8 — is still far below healthy airflow targets. With room 8 at 1.0 air change per hour, kids’ and staff’s viruses in their respiratory aerosols linger for over 2 hours and 18 minutes.
At 1.0 air change/hour, 2 hours 18 minutes is how long it takes for the HVAC system and Intellipure air purifier to clear out 90% of the respiratory aerosols being produced when kids and staff breathe, talk, sing, cough and sneeze.
With only one air purifier per classroom:
✘ Worst-airflow classroom (room 8) is still only 1 air change per hour
✘ 3 more Rieke classrooms have less than 2 air changes per hour
✘ 7 classrooms are between 2 and 3 air changes per hour & 2 more are between 3 and 6 – all below recommendations
If one Intellipure unit is running at its quiet noise level, only 6 classrooms meet our minimum goal for healthy ventilation and filtration of 6 air changes per hour or more, clearing 90% of aerosols out in 23 minutes or less.
Rieke needs two air purifiers per classroom to clean classroom air

With the two air purifiers per classroom placed and in use, over one-third of the school meets the minimum healthy air target
With two of the air purifiers the district already owns running at their best noise levels (one Intellipure at half speed and one Medify Pro at speed 2), 8 out of 19 Rieke classrooms would be at 6 air changes per hour or higher. Over one-quarter of Rieke's classrooms are above an excellent 8 air changes per hour if both air purifiers are in place. Viruses, mold spores, dust and allergens, wildfire smoke, and other air pollutants would clear out by 90% in as little as 12 minutes.
The median clean airflow with two air purifiers per classroom would be 4.7 air changes per hour. At 4.7 air changes, the typical classroom would still have insufficient clean air, resulting in too little respiratory protection. But this level of protection is much improved over the HVAC system alone or only one air purifier, and could be further strengthened by adding a third, classroom-friendly air purifier in rooms that fall short.
Two air purifiers make a big difference — but some rooms still fall short
In some Rieke classrooms, the baseline ventilation is so low that two air purifiers alone cannot fully solve the problem. Even so, using both an Intellipure and a Medify Pro still makes a major difference in these rooms, reducing exposure for students and staff compared with using only one unit, or none.For example, Rieke‘s worst-airflow classroom — Room 8 — is 2.9 air changes per hour even with two air purifiers. Although this is still below the minimum healthy air target of 6, it is far better than the 0.1 air changes per hour the room gets with no air purifiers running. Room 10 follows the same overall pattern: it reaches only 3.6 air changes per hour with two air purifiers, meaning that viruses, bacteria, asthma triggers, and other air pollutants linger in the classroom air for over 38 minutes. But without both air purifiers, Room 10 is only 0.8 air changes per hour. Room 11 is a third example with the same story. Even when operating two units, Room 11 is only 3.6 air changes per hour, but that airflow level is an important health protective improvement over the 0.8 air changes the room gets if relying on the HVAC system alone.
Visualizing how much air purifiers improve Rieke classroom airflow
The graphs below show how little ventilation most Rieke classrooms get without any air purifiers running. They also show how the addition of one air purifier per classroom shifts the rooms’ airflow rates higher but still leaves most rooms below health-based benchmarks for clean air. With two air purifiers per classroom, the pattern changes. Although two air purifiers still leave most classrooms short of 6 air changes per hour, having two units per room moves 8 classrooms into the healthy air range above 6, and the lowest airflow classrooms are much improved.
Number of classrooms vs air changes per hour
No air purifiers
HVAC only
Most Rieke classrooms have extremely poor airflow without air purifiers running. Most classrooms do not even reach 3 air changes per hour from the HVAC system.
One air purifier
One Intellipure air purifier running at its reasonable noise level still leaves over half of the classrooms with extremely poor airflow.
Two air purifiers
Over one-third of the classrooms have good levels of clean airflow with two air purifiers. Many classrooms reach 7 and even 9+ air changes per hour. And the below-target rooms get much better airflow with 2 units than they did with only one.
Next steps: support and strengthen Rieke's clean air practices and daily use of two air purifiers
Rieke received enough additional air purifiers that every classroom should have two units. The next step is strengthening and sustaining how Rieke uses daily air quality practices so that classrooms, lunchtime, after school activities, and school events consistently get clean air. Many schools are still building their understanding about how multiple air purifiers running quietly together are needed to clean the air in a full classroom of 20 or 30 kids. Some guidance on how and when to use both units has been shared at Rieke. In practice, running two air purifiers, instead of just one, moves clean airflow toward health-protective benchmarks, providing critical benefits of clean indoor air, such as reduced illness, improved learning, and better attendance.
Ongoing commitment to placing and using this clean air infrastructure needs action at all levels, from district leadership to the classroom. Parents, caregivers, and school staff also have key roles to play to support daily use of two air purifiers in Rieke classrooms and ensure clean classroom air. Join SIAFOS and our Rieke group to connect with others who care about clean, cool classroom air at Rieke.
The data shows how Rieke can improve air quality, reduce illness, and increase attendance
Why were second air purifiers delivered for every Rieke classroom?
In 2023, PPS received 3500 free air purifiers — enough additional air purifiers to provide a second unit for every classroom in the district and other learning spaces as well. Instead of fully delivering on that commitment, previous district leadership used a flawed decision-making process that sent most units into storage rather than into classrooms. Rieke was one of 28 schools whose units were delivered without being sent to storage first.
However, for 68 other schools, errors in airflow calculations, inappropriate averaging methods, and misleading communications under previous leadership resulted in PPS erroneously concluding that most other schools in the district did not need second air purifiers. A full explanation of how the storage of air purifiers meant to be cleaning classroom air occurred, and how PPS can correct course is available at:
In our analysis that corrects gaps in PPS’s airflow report, we have fixed errors and calculated classroom airflows with air purifiers running at speeds teachers can actually use.
Our airflow analysis provides room-by-room airflows at Rieke when rooms have no air purifiers, vs. one air purifier, vs. two air purifiers.
See our full airflow analysis for Rieke Elementary School here.
Highlights from our comprehensive room-by-room analysis of Rieke airflows
- With no air purifiers, 12 out of 19 classrooms are below 3 air changes per hour
- The HVAC system only provides the library with 1.2 air changes per hour, and the cafeteria is 9.1
- With two air purifiers, 1 classrooms are still under 3 air changes per hour, and 8 meet or exceed our minimum goal of 6 air changes per hour
Other SIAFOS analyses, reports, and campaigns
Learn more about indoor air quality in PPS with some of our other analyses, reports, and campaigns:
McDaniel High School Air Quality Report — our 144-page flagship report using the McDaniel cluster as a case study for districtwide problems, and solutions, for clean air
Benefits of Clean Indoor Air — improving air quality in PPS will increase student performance, reduce absences and educator sick days, improve health for students, staff, and surrounding communities, improve equity, and help mitigate impacts of climate change
Teacher Feedback on PPS’s Fall 2025 Temporary Cooling Measures — report on our survey of teachers in the 15 schools that received temporary cooling equipment in the fall 2025 heat wave
Sign-On Letter to Show Your Support for Clean Air in PPS — add your voice to our public letter calling for health-based ventilation and air quality in PPS
Airflow 101 Handouts: Understanding Airflow Sources in the Classroom and How Using Two Air Purifiers Allows Quiet Speed Settings
Poor airflow in Rieke and other PPS schools is why we worked with parents across the district in spring 2023 to advocate that PPS classrooms need additional, high quality air purifiers to provide safe air to kids now, when HVAC system overhauls will take the district years to do in all schools and a mix of ventilation from HVAC systems and in-room filtration is the best approach for clean classroom air in both newly modernized buildings and older buildings alike. Just as we were advocating to the school board for the need for additional filtration capacity in PPS classrooms, the Oregon Health Authority announced a program offering free Medify air purifiers to any K-12 schools in Oregon. When it became clear that district staff were not planning to sign up for any of the free air purifiers from OHA, we made the case for why Rieke needed these additional units. Parents from across the district joined SIAFOS in advocating that the district take full advantage of the program.
How can you help with clean air for Rieke?
Let’s support Rieke in using clean air tools well — Sign up to help ensure air purifiers are in place and running quietly to keep Rieke classroom air clean!
Two air purifiers running at quiet settings in each classroom would provide more air filtration to the 12 Rieke classrooms that do not even get 3 changes of air per hour and the 6 classrooms that only get between 3 and 6! Using multiple air purifiers would also ensure Rieke‘s library and other key spaces get better air quality, too.
Join us to be part of a group of parents and community members advocating for strategic, effective, and science-based planning for sufficient ventilation and filtration capacity in PPS schools — including Rieke. PPS air quality efforts have cycled between strong progress as well as periods of inaction and missteps. We are now working more collaboratively with district leadership, yet long-standing gaps in ventilation and air filtration persist across the district — which is why parent, staff, and community involvement at the classroom level, school level, and district level remains so important.
Changing our schools in PPS to have good air quality practices only happens when families and staff work together. When you join us, we’ll connect you with others and share simple processes that help PPS kids and staff, including kids and staff at Rieke, learn and work in classrooms with cleaner air, less illness, and healthier learning environments. Sign up below to join our organizing for PPS air quality!
*Notes on our numbers
Air changes per hour given on this page are “equivalent” and include ventilation and filtration. These numbers are based on the district’s airflow report for Rieke, conducted in August 2021 (available at safeairoregon.org/original-airflow-reports) but corrected gaps and errors.