Airflow reports that did not account for air purifiers only being usable at half speed.
Rooms with substandard ventilation that were overlooked entirely for getting an air purifier, and still remain with no air purifier.
Elementary schools like Rosa Parks, Hayhurst, Woodmere, and more being left with the majority of their classrooms letting kids’ viruses linger in the air for over an hour, even with air purifiers running.
The district not publishing final airflow reports for 21 schools – until our public records requests prompted them to.
We’re advocating to solve problems with indoor air quality in PPS.
PPS’s problems with poor air quality and what we’re doing about it
Problem:
PPS’s airflow reports are a wealth of quality information about airflow in nearly every room of the district, but the reports contain gaps and errors in the measurements and calculations of effective air changes per hour
What we’re doing about it:
We have completed appropriate and QA’d analyses of every elementary, middle school, and K-8 school that had an airflow report completed, and have that data available and at the ready for sharing with parents and staff. We also have an analysis demonstrating the major error in the high school airflow reports, and we are working on a comprehensive re-analysis of high schools where the airflow report still apply.
Read more about Addressing gaps in PPS ACHe measurements and calculations
Problem:
Information about air quality and ventilation in PPS schools is disorganized and hard to find on the district website
Solution:
We have a running history of air quality documents, links, reporting, meetings, and testimony for advocates who want to dig deep and put their hands on relevant documents and claims from the district. We will strive to continually add relevant memos, district communications, and meetings as there are more developments.
Find articles, memos, district reports, former SOPs, etc in Full history of documents and links
Look through HVAC work orders for the 2022-2023 school year through spring
Addressing gaps in PPS airflow measurements and calculations
Before resuming in-person learning in 2021, PPS had airflow testing conducted in nearly every room of every PPS building. Each room in the airflow reports has two different types of measurements of total effective air changes per hour. Note that we generally refer to effective air changes per hour as simply “air changes per hour.” One measurement of air changes per hour was for the HVAC system only. The other measurement was intended to be total air changes per hour if the one air purifier originally assigned to the room is run at full speed.
We have done a base analysis for PPS schools that corrects for three basic gaps in these airflow reports as originally published by the district:
- The Intellipure and Medify air purifiers we have in PPS cannot be run at full speed in classrooms and classroom-like settings. PPS teachers do not run these units at full speed. For Intellipures, half speed is the setting at which noise from the unit generally does not compromise learning, and Medify units generally do well in classrooms on speed 2. Our corrected calculations use specifications obtained from the manufacturer for clean air delivery rate at different speed settings to calculate air changes per hour with a generous estimate of Intellipure run at half speed and a precise value for Medify units run at speed 2. Also note that the high school reports’ full speed calculations use an incorrect clean air delivery rate even for full speed, and we also correct for that when we calculate or use full speed airflows.
- In 16 schools, airflow reports were done prior to the school being upgraded to MERV 13 filters, and calculations used the old MERV 8 efficiency factor in PPS’s reports. The district has now stated that all classrooms have been upgraded to MERV 13’s. For schools that were not upgraded at the time of airflow measurements, we have run a set of calculations of air changes per hour that use the generous MERV 13 efficiency factor used in the district’s airflow reports, to estimate the room’s current airflow.
- There are haphazard errors in the district’s reports, and many rooms that were excluded from measurements because of the room type (storage rooms, electrical rooms, mechanical rooms, etc) were marked as having a zero for airflow, rather than an appropriate marking of a hyphen. Likewise, sometimes there are rooms that are occupied and used by students and staff were overlooked for airflow measurements. Our calculations note and correct for errors as we find them, and we worked to try to be consistent about excluding rooms such as storage, closets, electrical, etc, while doing reasonable estimates for rooms that were overlooked but should be included.
Converting and correcting the PDF’s of the district’s airflow reports into Google Sheets also allows us to do analysis – summary statistics, graphs, calculations of how much different air purifiers would improve airflow, and other options for looking at what the district has or has not accomplished.
PPS schools have great need for additional filters – as of 2023, 597* kindergarten through 8th grade classrooms grossly lacked adequate fresh air from outside, and even with the Intellipure air purifiers the district added, these classrooms remained under 2 or 3 air changes per hour, while another 1111* kindergarten through 8th grade classrooms were only 3 to 6 air changes per hour. See the analyses we’ve shared here.
*597 / 1111 classrooms and counting …
As we do deeper dives into different schools when parents join our group and reach out to us for details about their school, we continue to discover schools in which PPS’s airflow report has an error for one or more classrooms.
Storage closets incorrectly designated as classrooms. Classrooms that PPS skipped entirely for any measurements whatsoever. PPS getting the room dimensions for a classroom wrong.
Both of these totals have creeped up by one or two from our original estimate for the March 21 school board meeting of 595 classrooms below 3 air changes per hour and 1110 classrooms below 6 air changes per hour. These total numbers may very well continue to change as parents identify errors that PPS made in the report for their school, HVAC systems get comprehensive overhauls, and buildings get re-built. However, HVAC system upgrades and building new building often does not improve these numbers. Our McDaniel Air Quality Report demonstrates poor airflows even in modernized buildings. So 597 / 1111 was our best estimate in 2023, and we are confident that air purifiers are critical to improving these stats.
These totals for elementary, middle school, and K-8 classrooms under 3 and between 3 and 6 air changes also do not include ACCESS Academy. ACCESS lacks a current airflow report, and that is one of the gaps in data that the district needs to fix.