Using IAQ Technology to Improve Air Quality in Our Schools
The COVID-19 pandemic has increased awareness of indoor air quality and schools are being required to take steps to improve existing HVAC systems. According to the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), changes to building operations, including the operation of heating, ventilating, and air-conditioning (HVAC) systems, can reduce airborne exposures.
The ASHRAE Epidemic Task Force has created guidelines to help designers plan for improvements to indoor air quality and to slow the transmission of viruses via the HVAC systems. Key components of those guidelines for school systems are highlighted below.
School Building Reopening Basics
As part of their guidance, ASHRAE is recommending that HVAC systems in school and higher education facilities operate in occupied mode in these situations as school buildings reopen:
- Any time staff or others are inside the building
- For 24-hours, if systems have operated during closure period
- Up to one week before occupancy, if systems have been shut down, to bring temperature and humidity under control before occupancy
HVAC Cleaning and Air Flush Protocol
The required daily air flush prior to occupancy requires that all mechanical systems be operated in occupied mode for minimum of two hours prior to occupants entering the building. The ASHRAE guidelines also include a cleaning checklist divided into monthly tasks for HVAC system equipment including boilers, water systems, chillers, cooling towers, steam distribution systems, air handlers, pumps, RTUs, and other components.
Retrofit Design Recommendations
Retrofit guidelines to improve air quality and to slow virus transmission through HVAC systems should focus on increasing outside air to the spaces, treating return air or supply air to spaces via mechanical filtration, and maintaining indoor comfort as defined by the design temperature and relative humidity. Winter classroom design guidelines state 72 degrees Fahrenheit with 40- 50% RH while summer classroom design guidelines require 75 degrees Fahrenheit and 50%-60% RH.
MERV Rating Upgrades
Minimum efficiency reporting value (MERV) ratings measure how effectively an air filter stops dust and contaminants from passing through the filter and into the air. As part of the guidance to mitigate the risks for COVID-19 exposure inside buildings, ASHRAE is also recommending that the air filters in schools be upgraded to MERV 13, which provides a 67% improvement over MERV-4. The upgrade to MERV 13 significantly reduces the risk of occupant infection from viruses and bacteria.
Indoor Air Quality (IAQ) and Ultraviolet Light
Incorporating IAQ technologies can help school systems achieve even better air quality. Since the late 1800’s, studies have shown that UV radiation impacts the ability of pathogens to reproduce. These pathogens include microorganisms such as viruses, mold, fungus, and bacteria. The peak germicidal action occurs near 270nm, which is in the UVC range. While air filters do play an important part in trapping such pathogens, UVC delivers the best results in reducing airborne pathogens by sterilization. UVC LED systems are effective against SARS-CoV-2, influenzas, and other pathogens.
UVantage™ is a UVC-based sterilization solution that operates at the heart of the HVAC system, sterilizing pathogens effectively, efficiently, and safely. UVantage works seamlessly with existing HVAC systems to sterilize the airstream and it’s built into the blower so there is no risk of exposure to harmful UV lights. As an HVAC blower with integrated UVC LED and control, UVantage uses an ideal location for cleaning the air before it’s distributed through ducts. UVC sterilization also provides cleaning of the blower wheel and adjacent filter.
UVantage, along with fresh air, filtration, and proper operation of the HVAC system, can help you achieve cleaner indoor air in your school building.