Ventilate optimally where children go to grow.

As of May 2021, the CDC recommends schools continue to use a layered approach of SARS-CoV-2 prevention strategies as outlined in its Operational Strategy for K-12 Schools until further notice. Evidence suggests that, when properly implemented, these strategies can limit transmission. Amongst detailed points on masking, handwashing, and physical distancing, the buildings themselves play a key role in encouraging a healthy environment. In addition to stringent cleaning standards, proper ventilation is vital to limiting transmission of the virus that has upended our lives, as well as other pathogens and allergens.


School building ventilation recommendations.

Having been involved in the engineering application and school district-wide control of large magnet high school ventilation projects, Haglid Engineering has always taken a great interest in healthy indoor air quality. After all, studies show that poor IAQ can contribute to less-than-ideal cognition—the last thing you want while trying to educate the next generation.

When it comes to school building ventilation, the CDC abdicates quite a bit to the American Society of Heating, Refrigerating, and Air-Conditioning Engineers. Chief among recommendations is providing acceptable indoor air quality, as defined by ANSI/ASHRAE Standard 62.1-2019, for the current occupancy level for each space.

Further CDC recommendations suggest the following:

  • Set HVAC systems to bring in as much outdoor air as your system will safely allow. Reduce or eliminate HVAC air recirculation when practical and with expert HVAC consultation.
  • Increase the HVAC system’s total airflow supply to occupied spaces when you can. More airflow encourages air mixing and ensures any recirculated air passes through the filter more frequently.
  • Disable demand-controlled ventilation (DCV) controls that reduce air supply based on occupancy or temperature. This way the air supply will remain constant throughout the day.
  • For simple HVAC systems controlled by a thermostat, setting the fan control switch from “Auto” to “On” will ensure the HVAC system provides continuous air filtration and distribution.
  • Consider running the HVAC system at maximum outside airflow for 2 hours before and after the building is occupied to refresh air before arrival and remove remaining particles at the end of the day.

Excellent recommendations? Certainly. There’s just one problem: Without modern HVAC and Building Management Systems, implementing some of them isn’t so practical if you’re after thorough, effective compliance in school districts with failing infrastructure.

Importance of a Building Management System (BMS) in school buildings.

A BMS is a computer-based, building-wide tool that monitors mechanical and electrical systems such as lighting, HVAC, power, security, and fire alarms. As pertains to HVAC, a modern BMS will control temperature and humidity, airflow, fans, and dampers. Run optimally, a BMS can reduce a district’s energy budget and reallocate those funds toward immediate academic needs.

The effectiveness of CDC ventilation recommendations depends on the capabilities and age of a building’s BMS as well as its HVAC equipment. Unfortunately, in a report on U.S. infrastructure, the American Society of Civil Engineers (ASCE) notes that 53% of public school districts report the need to update or replace multiple building systems including HVAC (41%). What can be done?

ASCE advises the following solutions:

  • The U.S. Department of Education should coordinate with state agencies and local school districts to obtain and publish nationwide statistics on school infrastructure at regular intervals.
  • School districts should focus on Life-Cycle Cost Analysis (LCCA) principles in the planning and design processes to evaluate the total cost of projects.
  • Design new campuses for the lowest net present value cost that includes lifecycle O&M in addition to capital construction.
  • Implement building condition assessment of existing school infrastructure.
  • Budget for the total cost of ownership and train facilities staff to implement these policies.
  • School districts should develop capital planning frameworks that can be nimble and responsive to changing technologies and demographics, in order to optimize learning environments and consider the holistic needs of the community.
  • Continue to encourage school districts to adopt regular, comprehensive major maintenance, renewal, and construction programs, and implement preventive maintenance programs to extend the life of school facilities.
  • Explore alternative financing for public school facilities, including lease financing, as well as ownership and use arrangements, to facilitate school construction projects.


The pandemic threw us many curves and uncertainties, but one point is clear: We need to do better in keeping our kids in school safely, not just for everyone occupying school buildings, but for mental health reasons as well. To do that with an airborne virus circulating will take excellence in HVAC.


Interested in helping your school and/or district make changes to save money, keep kids safely in school, and lower education’s carbon footprint? Give Haglid Engineering, LLC a call. We have the expertise to upgrade building systems and the will to go the extra mile for the next generation.