As the senior living design industry heads into a new year, infection control remains a top consideration. Charter Senior Living (Naperville, Ill.) and Erdman (Madison, Wis.) recently partnered to identify best practices to keep communities’ residents and staff safe. Here, solutions tied to HVAC systems as well as other key design elements are explored.

Assess the HVAC system
Mechanical ventilation systems are intended to improve air quality through air cleaning and dilution techniques. However, they can also contain or spread aerosolized germs with self-created air currents. To improve a ventilation system for infection prevention, here are three strategies to consider:

1. Filtration (air cleaning): An initial HVAC assessment can determine the filtration level for each ventilation component. The two common filtration ratings that you want to be familiar with are: Minimum Efficiency Reporting Value (MERV) and High Efficiency Particulate Air (HEPA).

Using a MERV 14 filter will significantly improve the air quality over a MERV 8 (or lower) rated filter. In many situations, you will likely need to replace only existing filters. In other situations, the HVAC unit’s filter rack, which houses the filters, may have to be altered to house the new filter type, which can be larger. If the latter option is impractical, consider a separate filter rack installed in the duct system to handle an upgraded filter. Additionally, higher rated filters typically require more fan horsepower to maintain the same airflow as regular filters. In turn, a system assessment should investigate how existing fan motors could be impacted and if changes to fan horsepower would be required.


HEPA filters provide the highest level of cleaning and protection. However, most systems found in senior living are unable (or it is impractical) to add them because HEPA filters are deeper and require more fan horsepower than can be typically accommodated. Nevertheless, there are many types of portable HEPA-filtered recirculating units that can be used to provide increased dilution.

A vertical terminal air conditioner (VTAC) can also improve air quality. VTACs installed in hidden, enclosed closets can improve a resident apartment’s aesthetics and acoustics over wall-mounted package terminal air conditioners (PTAC). Some VTACs are capable of accommodating the higher rated MERV 14 filters. As part of a new community for Charter Senior Living in Oswego, Ill., the project team is installing VTACs with MERV 14 filters to provide these added benefits.

2. Dilution: Dilution occurs by replacing contaminated air with clean air. Outside air and highly filtered air are considered clean air. HVAC systems in senior living communities should be evaluated to determine if they are operating at their targeted amounts of outdoor air because this is commonly reduced to address heating and cooling issues. At the same time, the assessment should identify opportunities to increase the outside air without jeopardizing the indoor temperature or humidity levels.

As we are still battling COVID-19, it’s recommended to also maintain the outside air even during non-occupied hours to continue providing clean ventilation to indoor areas. To do so, identify systems that lower the outside air based on the time-of-day or sensing devices and modify controls so they maximize their filtration and dilution of the facility throughout the entire day.

HEPA-filtered recirculation units are another option to increase indoor air dilution. Care needs to be taken in the selection and specifications of units to ensure the desired increased level of dilution. The sound from these units also needs to be considered when determining their location.

3. Air disinfection: Ultraviolet (UV-C) germicidal irradiation, bipolar ionization, and photocatalytic oxidation technologies for air disinfection have been around for a long time, but have regained attention during the pandemic. Several options are available. Portable UV-C units are used to clean areas after hours or following a potential exposure and require special personal protective equipment (PPE) to prevent damage to the eyes and/or skin from overexposure. Permanent UV-C units, which can be mounted high above the floor, are often used for larger spaces such as dining rooms to reduce potential contaminates circulating within an area.

Bipolar ionization can be applied to ventilation systems to clean air within the unit. It’s also been found that ions can travel within the airflow and can be delivered into occupied spaces to disinfect the air in a specific area. Bipolar ionization is usually an easy retrofit to most ventilation systems and the cost is typically modest.

However, it should be noted that these systems have been reported to range from ineffective to very effective in reducing airborne particulates and acute health symptoms. Independent scientific peer-reviewed studies don’t currently exist on this emerging technology, and manufacturer data and marketing claims should also be carefully considered. It’s not well understood if there are any adverse effects from this technology. Additionally, it’s important that a bipolar ionization device is certified to not generate ozone.

Similarly, photocatalytic oxidation units can be placed within ventilation systems to further disinfect air being supplied to rooms. These are primarily used in new construction for large ventilation systems, as many existing systems wouldn’t have room to accommodate them.

Other key strategies
Additional considerations to prevent the spread of infection include reducing the potential for contact transmission on surfaces. Low- and no-touch hardware and switches should certainly be considered. These devices allow for voice activation or “app” activation to prevent multiple touches by people.

Smart materials, such as silver and copper ion antimicrobial technology, have been shown to inhibit the growth of damaging microorganisms and can be applied in solid surfaces that receive regular contact, such as bed rails, door handles, grab bars, switches, porcelain, and textile-based materials to support infection control measures.

Adding handwashing and sanitizing stations outside of resident living spaces can be one of the most effective strategies to mitigate the spread of infection. However, the greatest challenge is encouraging a behavioral change by residents and staff to make the use of such stations a habit. To resolve this, add signage or other visual cues at sanitizing stations.

Whether you’re building new or renovating an existing facility, designing and planning for contained neighborhoods is another key to control the spread of germs. This can be achieved by rearranging furniture and using partitions to compartmentalize normally large spaces, such as staff work areas, dining rooms, and amenity spaces. Additionally, residents can be reminded to maintain safe distances from each other and room capacities can be minimized to reduce the spread of germs.

Finally, technology must be considered to help control the instances of incoming contaminants into a community. The use of visitor management systems to accept and track people at check-in and entry points is paramount to keep residents and staff safe. These systems leverage facial recognition, mask detection, temperature scan sensors, and contact tracing using artificial intelligence.

Beyond this, technology can also play a role to keep residents healthy as they’re isolated from their social connections. Whether it’s family or fellow community residents, a resident’s social network is a lifeline that cannot be cut off. Offering video and telecommunication options is paramount for the health and well-being of residents.

Together, considering all of these solutions can help deliver a comprehensive response to preventing the spread of infection within senior living communities.

Todd Hudgins is senior vice president at Erdman (Madison, Wis.). He can be reached at thudgins@erdman.com.

Michael Meteyer, PE, is engineering manager at Erdman. He can be reached at mmeteyer@erdman.com.