Airflow and Ventilation Overview

  • September 8,  2021

     Airflow and Ventilation Assessment and Response

    In February 2021, when we were in distance learning, district leadership proactively initiated a review of our HVAC systems to gain a better understanding of ventilation system conditions across the district and make any necessary mitigations or suggested improvements.

    This effort was also driven by the need to make repairs and replacements across the district due to our aging infrastructure, and thanks to voter approval, we are making improvements across the district.

    The assessment process began last February and entailed outside experts that surveyed District schools, took sample readings, recorded conditions and identified any ventilation deficiencies and estimated air flow and air changes per hour in our buildings. The district used this report to identify areas that we could mitigate to meet state recommendations and to improve our HVAC systems for the long-term.

    The District received the reports in March and April 2021. The results demonstrated that ventilation units in Centennial Schools are generally providing 3 air changes per hour or more in classrooms. The assessment revealed some ventilation systems were in need of repair, some were unable to provide at least 3 air changes per hour (ACH), and some classrooms did not have a ventilation unit. Last spring, Centennial School District immediately deployed HEPA air filters to enhance air cleaning in areas needing mitigation. Furthermore, the district purchased HEPA filters for all classrooms and areas where students congregate. Please refer to the reports below for building specific survey results.

    Alignment with State Guidelines

    The Oregon Department of Education’s (ODE) Ready Schools, Safe Learners Resiliency Framework ventilation and airflow guidance states, “ODE and OHA strongly advise schools to ensure effective ventilation and improve the indoor air quality in schools by:

    1. Increasing the amount of fresh outside air that is introduced into the system;
    2. Exhausting air from indoors to the outdoors; and
    3. Cleaning the air that is recirculated indoors with effective filtration methods (e.g., HEPA filters) to remove virus-containing particles from the air.”

    At all of our sites, we’ve taken steps that align with ODE’s resiliency framework by taking a multipronged approach to enhance ventilation in our schools which includes:

    • Operating existing ventilation at the highest level allowable by the HVAC system.
    • Using portable HEPA filtering devices to supplement HVAC systems or in places where there is no HVAC system.
    • Increasing outside air through ventilation systems and windows.
    • Opening windows in classrooms and on busses to allow indoor air out.
    • Cleaning indoor areas through the deployment of portable high-efficiency particulate air (HEPA) filtration units to all classrooms and common areas.

    We’ve been working with ventilation and mechanical contractors to make repairs and maintenance to our HVAC systems, and working with our Bond project managers for major repairs and replacements where necessary.

    As a reminder, ventilation is one aspect of our COVID-19 mitigation strategy. Additional mitigation measures include:

    • Employee and student screening for symptoms
    • Universal indoor mask requirements
    • Enhanced cleaning and disinfecting
    • Hand hygiene
    • Vaccinations
    • Physical distancing
    • Ongoing student and staff training