“Protecting our voters and poll workers from increasing the spread of COVID-19 at polling places is essential to protecting the health, welfare, and safety of the entire population,” said Dennis Knight, ASHRAE Epidemic Task Force vice chair. “Many different HVAC system types are used in polling places, so adaptation of these guidelines to specific cases is necessary.”

The fact that voting takes place in a wide variety of locations poses a problem. Common settings include schools and churches. Many of these facilities have been closed since the middle of March, and their HVAC systems weren’t always in the best shape before that.

“We know that there is a lot of deferred maintenance in a lot of buildings,” Bill Bahnfleth, chair of ASHRAE’s Epidemic Task Force. “Schools are one type of building where maintenance has been an issue, and a lot of polling places are in schools.”

That said, buildings that have been unused may actually prove better choices — if reopened properly — than some locations used in the past. Large states, such as California, place polling places in all kinds of buildings, including car dealerships, fast food restaurants, laundromats, and even people’s homes. These unusual polling places present heightened risks, in some cases exposing vulnerable populations to possible contamination. For example, Bahnfleth himself votes at a local retirement home.

Stick With The Basics To Upgrade HVAC

Election authorities may want to consider alternative locations, Bahnfleth said. ASHRAE recommends spaces with larger areas for people to spread out and, if possible, a high ceiling to provide more volume for dilution. Election authorities should consider space with operable windows if there are potential ventilation issues.

There are some simple upgrades that can be make these facilities even safer. ASHRAE recommends replacing filters with those rated MERV-13 if it does not adversely impact system operation. Election authorities may also want to use portable HEPA air cleaners and UV lights in needed.

Of course, most election authorities lack the money to invest in new equipment, much less HAVC equipment. Bahnfleth said sticking with basics, like increasing outdoor air, will prove affordable. A good supply of outside air dilutes indoor contaminants, and ASHRAE consider this a first line of defense against aerosol transmission of COVID-19. If the polling place is not ventilated or poorly ventilated and filter efficiency is not good, consider opening doors and windows. If possible, some voting authorities should consider relocating all voting outdoors.

So-called “superspreader” events have taught ASHRAE a lot, Bahnfleth said. For example, an incident that infected 52 members of a Washington State choir shows the need for more frequent air changes — as many as five per hour. The HVAC and toilet exhaust systems should be running when the space is occupied. If the HVAC system cycles on/off with the thermostat, ASHRAE recommends running the fan constantly during occupied hours. An outbreak traced to a restaurant in China shows the risk of air currents in transmitting the virus, so ASHRAE recommends taking care in using personal fans for poll workers.

The elections will take place in early November, a time when cooler weather can cause buildings to become dryer. Bahnfleth said election authorities will want to maintain reasonable humidity at the polling places. He said 40 percent relative humidity seems to provide some protection against the virus.

Ultimately, other factors will play a greater role in preventing the spread of the virus at polling places, Bahnfleth said. These include limiting the number of people at each polling place, cleaning common spaces, requiring masks, and have people wait outside to vote.

“Anything you do to the building is over and above distancing and mask wearing and hygiene,” Bahnfleth said.