Apr 28, 2023 New ASHRAE Guidance Recommends UV-C to Improve School IAQ
New ASHRAE Guidance Recommends UV-C to Improve School IAQ
When it comes to better school air quality, ASHRAE wrote the book
In a 2023 document titled “Design Guidance for Education Facilities: Prioritization for Advanced Indoor Air Quality,” ASHRAE Technical Committee 9.7 (TC9.7) members recommend UV-C as an effective strategy to improve school indoor air quality (IAQ).
ASHRAE’s comprehensive, detailed set of recommendations provides instruction from industry experts to owners, operators, designers and professional service providers on how to best implement IAQ improvements, including risk mitigation strategies, in educational facilities.
Technical committee members identified the addition of UV-C to school HVAC systems not as an optional frill, but as a base minimum IAQ improvement. And that makes perfect sense, because raising IAQ in schools has been correlated with significant improvements in student and teacher health and performance.
A recent study from the LANCET COVID-19 Commission, “Designing Infectious Disease Resilience into School Buildings Through Improvements to Ventilation and Air,” stated: “In addition to decreased airborne infectious disease transmission, research shows that ventilation and air cleaning improvements are likely to lead to improved academic performance, fewer missed school days for students, higher scores on cognitive function tests, and many benefits for teachers including decreased respiratory symptoms, increased teacher retention, and improved morale.”
UPPER ROOM UV-C: A SMART SOLUTION FOR SCHOOLS.
In particular, ASHRAE’s document recommends that educational institutions consider installing UV-C in spaces that have high occupancy or require frequent changeovers, yet where it may not be practical to achieve recommended air volumes. In these situations, Upper Room UV-C can provide additional air changes per hour, and studies have shown that these units can perform at the equivalent of 10 to 16 air changes per hour. Because people generate many of the infectious airborne pathogens in a space, these upper-room systems are very effective at killing in-room, airborne microorganisms.
The committee also categorized HVAC filtration upgrades such as MERV 13 filters as a very high priority task and noted, “By improving the filtration in the air handlers, it is possible to decrease the chance of aerosolized viral particles being spread through the air distribution system.” However, while higher filtration is more effective, it may not be practical because there are diminishing returns in the improvement of particulate removal and increases in static pressure and cost.
WITH UV-C, MERV 8 IS ENOUGH.
Happily, there is a simple, affordable, easy-to-implement way to incorporate MERV 13-level pathogen removal performance in many aging school HVAC systems that cannot handle the high airflow restrictions and static pressure commonly associated with high-efficiency MERV 13-rated air filters.
Third-party, independent testing has shown that combining UV-C with a MERV 8 prefilter exceeded a 99% average single-pass reduction of the aerosolized SARS-CoV-2 virus, surpassing the removal rate of the MERV 13 filter health agencies and industry advocates recommend.
Plus, the low-pressure drop associated with the MERV 8 air filter significantly reduces fan horsepower and cuts energy consumption and maintenance costs.
To download a copy of the ASHRAE recommendations, visit https://www.ashrae.org/file%20library/technical%20resources/free%20resources/design-guidance-for-education-facilities.pdf
Posted Apr. 28, 2023