4 technologies for improving building sanitization in a post-pandemic society
The long-term impact of the COVID-19 pandemic will transform future building design practices to prioritize public health and mitigate the risk of spreading infection. Technologies that have long been utilized in hospitals and medical centers, but have not been widely embraced in other sectors due to additional costs, may see wider integration in other public buildings.
Healthcare settings have more rigorous cleaning regimens to control hospital acquired infections (HAI’s) and supplement hand cleaning of rooms with automatic and systems-based approaches. This method can remove the chance of human error. Here are four techniques and technologies that can be easily adapted from healthcare facilities to other settings:
Some tools and techniques used to keep hospitals clean could soon be incorporated into other public buildings.
1. Clearing the air
The use of High Efficiency Particulate Air (HEPA) filtration plays a key role in limiting the transmission of diseases. COVID-19 is transmitted from human to human by droplets expelled from the lungs via aerosols. This is caused from activities such as breathing, coughing, sneezing, smoking, and vaping. In still air, these droplets are found to fall to the ground within six feet of the person generating them. However, airstreams created by HVAC systems can transport them farther. While HEPA filters are only partially effective against viruses due to their size, they can trap the larger droplets on which the virus travels. It is important to place this type of filtration in air streams before the droplets can be deposited in HVAC units. These units are commonly found in hotels, senior housing facilities, condominiums, apartment buildings, residential additions and sunrooms, and cannot be easily disinfected.
Hospitals and commercial buildings have also employed the use of high-output germicidal ultraviolet (GUV). GUV uses short-wavelength ultraviolet (UV-C) within air-handling units (AHU’s) to reduce airborne pathogens. The combination of HEPA filtration and UV-C significantly reduces the risk of spreading viruses.
2. Germicidal Ultraviolet
GUV also has other applications for removing pathogens. UV-C kills organisms and inactivates viruses on the surface of objects. So, its effectiveness depends upon line-of-sight and distance from the source—areas not directly exposed are not disinfected. Technology using UV-C includes:
- High-output UV-C robots that can decontaminate a room in approximately 30 minutes. These robots have proven highly effective for sanitizing patient rooms in hospitals. However, they cannot be used in occupied spaces because the intensity of light and time of exposure will cause damage to human skin and eyes
- Upper air fixtures using high-output UV-C lamps with louvers that can disinfect the air of an occupied space. The fixtures are mounted on the wall, ceiling, or in corners of rooms and have louvers that direct the light towards the ceiling and use convection forces to disinfect air above occupants.
To improve public health and safety, these practices will need to be more widely incorporated into both design and business operations.
3. Vaporized hydrogen peroxide
Another room sanitation method used in healthcare settings is vaporized hydrogen peroxide (VHP) delivered via mist foggers or robots. This technology creates a cloud of hydrogen peroxide which is 80-90 percent effective in killing microorganisms.
Like high-output UV-C systems, occupancy without personal protective equipment (PPE) is not possible. If occupants must be present, buildings can use ionized hydrogen peroxide (iHP) systems which create a plasma that has the same efficacy as VHP but does not require PPE. iHP systems can be installed in central AHU’s or as terminal units within an occupied space. They appear to be the most effective—and easily employed—method for surface and airstream disinfection. This is a newer technology than VHP and has not had widespread implementation to date. Since spaces treated with iHP can be simultaneously occupied, it is a logical choice for retail and commercial settings.
4. Antimicrobial surfaces
It is currently reported that the coronavirus can live for hours to days on touch surfaces, such as door handles, grab bars, and countertops. It will live for up to five days on common hardware metal finishes, but only about four hours on copper and silver ion components. These finishes have been available for over a decade, but the slightly higher cost for these materials and perceived lack of widespread need for antimicrobial touch surfaces has made their use rather limited.
The use of naturally antimicrobial materials for high-touch points will likely be incorporated into future building designs.
The installation of automatic door operators—although an added cost for projects—is another simple approach employed in hospital pharmacies and high-use entrances/exits to limit the transmission of contaminants. Post-pandemic design practices should consider their use to reduce the likelihood of transmission by touch.
The broader impact on design
Technology can help us reduce the risk of spreading communicable diseases. But, it needs to be combined with social distancing and sanitation of touch surfaces to control the spread of viruses like COVID-19. To improve public health and safety, these practices will need to be more widely incorporated into both design and business operations.
Specifically, we need to rethink how we integrate social distancing in the design of our buildings with elements like:
— Making aisles wider in retail settings
— Moving away from 24/7 operation of retail operations to allow for daily deep cleaning
— Planning for one-way flow through public spaces
— Reducing the density of seating in restaurants and promoting take-out orders
— Providing larger cubicles in open office planning
— Supporting deep cleaning of hoteling areas between occupants
— Creating smaller classroom sizes in schools and promoting more widespread distance learning
— Providing larger common areas in public venues along with temperature-controlled and weather-protected outdoor common areas
— Moving away from window A/C units in hospitality, educational, and residential spaces.
We have the opportunity to apply the lessons we have learned from fighting this pandemic to our future building planning, designs, and operations. These changes will ultimately improve the quality and safety of our built environment while helping prevent the rapid spread of future diseases.