ASHRAE Epidemic Task Force Offers Guidance for HVAC Systems at Polling Places

As election season continues throughout the nation during the pandemic, the ASHRAE Epidemic Task Force is offering HVAC and water supply system guidance for polling places.

ASHRAE’s Building Readiness guidance provides practical information and checklists to help minimize the chance of spreading SARS-CoV-2, the virus that causes COVID-19.

Here is a summary of key general recommendations related to HVAC and water supply systems for polling places:

• Space Selection: Select a space with larger area for people to spread out and, if possible, a high ceiling to provide more volume for dilution. Consider space with operable windows if there are potential ventilation issues.
• Inspection and Maintenance: Consider assessing the condition of systems and making necessary repairs. All building owners and service professionals should follow ASHRAE Standard 180-2018 “Standard Practice for the Inspection and Maintenance of Commercial HVAC Systems.”
• HVAC Operation: The HVAC and toilet exhaust systems should be running when the space is occupied. If the HVAC system cycles on/off with the thermostat, consider running the fan constantly during occupied hours. If toilet exhaust is controlled by manual switches, leave the fan running for 20 minutes after use, or consider setting the switch to “on” and use signage that directs not to change the setting.
• Ventilation: A good supply of outside air, in accordance with ASHRAE Standard 62.1-2019, to dilute indoor contaminants is a first line of defense against aerosol transmission of SARS-CoV-2. Pre- and post-occupancy purge cycles are recommended to flush the building with clean air. If the polling place is not ventilated or poorly ventilated and filter efficiency is not good, consider opening doors and windows, and consider re-locating all voting to the outdoors.
• Air Distribution: Air flow distribution should not cascade air from the face of a person onto others, so take care in using personal fans.
• Filtration: Use of at least MERV-13 rated filters is recommended, if it does not adversely impact system operation. If MERV-13 filters cannot be used, including when there is no mechanical ventilation of a space, portable HEPA air cleaners in occupied spaces may be considered. Also consider portable air cleaners in locations with more vulnerable staff.
• Air Cleaning: Air cleaners such as germicidal ultraviolet air disinfection may also be considered to supplement ventilation and filtration. Technologies and specific equipment should be evaluated to ensure they will effectively clean indoor air without generating additional contaminants or negatively impacting space air distribution by creating strong air currents.
• Temperature and Humidity: It is desirable to set the thermostat at the higher end of the comfort zone, 75-78 F and maintain relative humidity between 40-60%.
• Energy Use Considerations: In selecting mitigation strategies, consideration should be given to energy use as there may be multiple ways to achieve performance goals that have greatly different energy use impact. Control changes and use of energy recovery to limit or offset the effect of changes in outdoor air ventilation rate and filter efficiency may reduce or offset energy and operating cost penalties.
• Water System Precautions: Buildings that have been unoccupied could have stagnant water, and water systems should be flushed to remove potential contaminants. Utilizing ASHRAE Standard 188 and Guideline 12 can help minimize the risk of waterborne pathogens such as legionella.

The complete Epidemic Task Force Guidance document for polling places can be found here.

To view complete guidance on HVAC and water supply systems in polling places, along with other COVID-19 resources, visit ashrae.org/COVID-19.