ASHRAE Pandemic Plan for Educators
Goal: Protect Students and Staff
The Challenge
There are many opinions on what should be done to prevent viruses from spreading within the classroom, but the elephant in the room is what is being done to prevent HVAC systems from accidentally spreading the virus within and between rooms. ASHRAE has laid out detailed plans in five different areas to make sure that all risks are accounted for to strategically address Indoor Air Quality (IAQ).
Until there is a widely available vaccine, let’s look at the ASHRAE guidance to determine what can be done in the interim to provide peace of mind and protection for both students and staff to achieve the goal of keeping minimizing transmission.
The ASHRAE Guidance
Aside from social distancing, masks and cleaning regimens, which are well known, ASHRAE outlines key steps to prevent indoor transmission of aerosols beyond the typical 6 feet of social distancing that can be exacerbated by HVAC systems transporting particulates further through the air.
The ASHRAE Epidemic task force recently published guidelines for schools and universities to facilitate the adoption of best practices to increase outside air to spaces and to treat return air with the objective of slowing the transmission of viruses via HVAC systems in order to prepare for the return of students and staff and to ensure educational buildings minimize the hazards of spreading viruses.
Indoor Air Quality (IAQ) Guidance
Specific to IAQ, ASHRAE recommends the target level for filtration for schools to MERV 13 or higher to remove a minimum of 75% of particle diameter size of 0.3-1.0 um. To ensure airflow performance when using MERV 13 or greater filters, it will be equally important to adjust the variable frequency drives to address the increase in static pressure for filters. In the case where MERV 13 filters cannot be retrofitted, other strategies such as providing HEPA filtration units to re-circulate air within the space or Air Ionization and/or UV treatment are options when MERV 13 filters cannot be installed.
Detailed ASHRAE Facility Space Strategies for Education Facilities
It is recommended to review ASHRAE guidelines that are specific to the type of education facilities spaces. Here is a glimpse of some of the key variables to consider for each space type.
1) Student Health Facilities: Increase ventilation rate to six air changes per hour (ACH) for the student health facility and take it a step further for temporary isolation rooms for ill patients to twelve air changes per hour along with exhausting all air in this isolation rooms to outdoors in order to prevent cross-contamination.
2) Laboratory Facilities: Verify all fume hoods and bio-safety cabinets are up to date on certification and conduct smoke tests in all spaces to verify airflow patterns.
3) Athletics Facilities: Increase outdoor air ventilation rates as high as possible and increase locker room airflow while maintaining negative pressure along with verifying that all locker room exhaust flows exceed ANSI/ASHRAE Standard 62.1.
4) Residence Halls: Consider HEPA/UVC portables and replace filters with MERV 13 or higher wherever possible. In addition, verify all outdoor airflows are well distributed (>0.1 cfm/sf)
5) Large Assemblies, Lecture, Theater Spaces: Besides replacing all filters with MERV 13 or higher and increasing outdoor air ventilation rates it’s important to verify exhaust airflows to a minimum of 1.0 cubic feet per minute (cfm)/ square feet (sf) for all toilets and locker rooms and 0.7 cfm/sf for all concession stands. And for rehearsal rooms, HEPA filter units are recommended.
Where to Start?
Without a strategic plan, everyone is reacting rather than responding to solve the challenge for achieving sufficient indoor air quality of university and K-12 buildings to prevent virus transmission. The questions educators and facility managers are asking is - Are we marching in lockstep in a common direction? Your IAQ choices can be summarized into three categories.
1) Good: At minimum, utilize MERV 13 filters along with increasing ventilation rates
2) Better: To go a step further to reduce the risk of transmission, utilize MERV 14 filters where possible and bring in as much outside air while balancing the requirement to maintain indoor comfort
3) Best: For the lowest possible risk, utilize HEPA filters in critical areas and humidify to 40% relative humidity if possible. The ultimate preventative measure, although you’ll have to weigh cost factors, is to install Ultraviolet Germicidal Irradiation (UVGI) and/or bi-polar ionization.
Maximizing Filter Longevity
The number one issue with upgrading filters (MERV 13 or greater and HEPA) is the cost. To offset the high cost, it is more cost-effective to replace filters on a just in time basis rather than a just in case basis based on a periodic replacement schedule. To determine if filters require replacements on a just in time basis, monitoring filter health based on differential air pressure sensors can easily identify when a filter is ready for replacement. Monitoring building health across your building portfolio can be accomplished using an automated smart building platform that continually monitors parameters such as differential pressure to indicate a filter is ready for replacement. In addition, automated rules can alert you to several Indoor Air Quality (IAQ) metrics to ensure that your building is operating at maximum performance at the lowest possible cost. To learn more about how that is done – Meet BOB – The World’s first Building Optimization Broker.
Check out Reopening Education Facilities eHandbook for more tips.
Meet the Author
Anthony Robinson | Strategic Business Development Director | Key2Act
15+ years advising clients on how to unlock the power of their data. Consult with mechanical services providers, building owners and energy services companies to unlock energy savings in their smart buildings
Authored an educational ePaper titled “Developing a Smart Building Strategy” to facilitate the conversation on best practices to develop an effective strategy.