Environmental Improvements: A Look at UVC & Other Technologies

The transition out of a state of pandemic has been particularly complex for facility managers. As building occupants rejoin their colleagues at their places of work, many landlords have been charged with optimizing the operational performance of their buildings to give peace of mind to their tenants. Simultaneously, organizations across the country are struggling to retain employees, which creates pressure for employers to increase compensation and benefits as well as improve the work environment for their employees. With Americans spending about 90 percent of their time indoors, it could be beneficial to employees to know the facilities they work in are striving to support their well-being. Providing environmental improvements that support the health and well-being of occupants can also benefit facility managers and building owners by helping to improve tenant retention.

Building occupants are more cognizant of air quality issues now than they were pre-pandemic. Facility managers and building owners have a variety of methods available to them for improving indoor air quality, often without incurring significant additional cost. The simplest approach is to increase fresh air ventilation, where possible. Bringing in and circulating clean, outdoor air to the indoor environment can help control pollutant levels, odors, humidity, and other factors that impact the health and wellbeing of occupants. Considerations to account for when seeking to optimize fresh air ventilation can be found through the EPA’s Clean Air in Buildings Challenge.

HEPA and MERV Filters: A Good Start for Capturing Particles
When increasing fresh air intake isn’t possible, facilities can improve their air quality through filtration. HEPA filters are widely considered the gold standard for removing airborne particles, and are particularly helpful for people with asthma, allergies or those who suffer from respiratory problems. A common misconception regarding HEPA filters is that they are unable to capture airborne bacteria and viruses. This is often due to the assumption that the filters act purely as a sieve and thus only prevent the transmission of particles larger than spaces between fibers. However, they also capture minute particles through diffusion – the intricate fibrous structure of the filter media knocks these particles out of the air stream and they become held through the phenomenon of Brownian motion, bouncing around inside the filter for perpetuity or until they become stuck on a fiber. It’s important though to use filters with a HEPA rating or a MERV rating greater than 13 when seeking to capture pathogens. It is also possible to install multiple filters in sequence to achieve a higher efficiency at capturing particles. For example, placing two MERV 11 filters (that are each 65% efficient for particles between 1 and 3 µm) in sequence would achieve a combined efficiency of 88% (for particles between 1 and 3 µm) – which is greater than the efficiency of a single MERV 13 filter (85%).

Ultraviolet Germicidal Systems: Kills or Inactivates Bacterial, Fungal and Viral Organisms
Facilities with a high risk of spreading pathogens, such as hospitals, schools, restaurants, or airports, or those with occupants particularly vulnerable to contracting an illness, such as assisted living facilities, should consider Ultraviolet Germicidal (UVGI) systems. Such systems can be a potent addition to disease prevention strategies as they go beyond capturing pathogens and use ultraviolet energy to kill or inactivate bacterial, fungal, or viral organisms. UV-based air disinfection stands out as a well-proven method of reducing pathogen spread since the 1930s and has been critical in the fight against drug-resistant infectious diseases in hospitals. For goals focused purely on disinfection, filter-less active air disinfection devices can also improve the number of air changes per hour (ACH) in an indoor space. ACH is a critical measure for effective air ventilation and disinfection. Filter-less disinfection devices deliver improved ACH and reduce maintenance cost over the long term.

There are several types of UVGI systems. The most common include passive upper air devices, HVAC-based systems, and portable units. Upper air UV is a straightforward system that can be effective under the proper conditions. A UV lamp in a specially designed fixture directs UV light across the upper air of the room (UV light does not retain energy well upon reflection, so the risk of exposure is limited). As particles pass repeatedly through the UV light they are inactivated through cumulative exposure. Keep in mind that there must be regular, and ideally steady, airflow to ensure the effectiveness of this type of system.

HVAC-based disinfection systems were traditionally employed to reduce microbial buildup on air conditioning equipment, but they are not the most effective at disinfecting the air in occupied spaces. While most of a facility’s air does pass through the HVAC system at some point, even strong ventilation has been shown to be ineffective at removing viral particles from the air. A study by the University of Minnesota regarding coronavirus-sized particles found that after a 50-minute simulation only about 10% of the particles were removed from a space with strong HVAC ventilation.

Portable UV air disinfection units enable simple transport between rooms with varying levels of disinfection requirements. Paired with another method of permanent air disinfection it can help to ensure proper air movement and maximize the quality of air in the space. As mentioned, for disinfection goals, filterless models improve the number of air changes per hour, a critical measure for effective air ventilation and disinfection, by reducing air resistance against a filter.

Before introducing any UV-C system into a space it is critical to consider safety implications. Any direct exposure to UV-C is dangerous and must be avoided, and UV disinfection lighting products with UV-C must be equipped with mechanisms to avoid human exposure. Devices that output 222 nm (Far UV-C) are the exception. Light in this region has been shown to be safe for both human skin and eyes, but products employing this type of energy are still in the early stages of use outside the laboratory.

LED Lighting Systems – Improves Indoor Environment While Reducing Energy Consumption
Beyond air quality adjustments, another option that has been shown to dramatically improve the indoor environment while also reducing energy consumption is to retrofit any existing fluorescent fixtures to LED lights or to upgrade existing LED lighting to incorporate more advanced controls such as dimming and color-tuning. LED lighting systems can provide more amicable and productive lighting, while more advanced lighting control systems can also quarterback building energy management. LEDs are particularly beneficial since their light output is the closest spectral match to sunlight currently available, resulting in better color differentiation, brighter whites, better color saturation and overall better color vision. LED lighting has also been shown to positively affect worker productivity and overall well-being, with numerous benefits to employees and organizations alike.

The implementation of one or more of these environmental improvement measures will help assure building occupants that your facility takes their health and wellbeing seriously.

Christopher Johnston is Director of Sustainability and Product Manager, Energy Focus, Inc.,  a leader in sustainable, energy-efficient lighting and controls systems and ultraviolet-c light disinfection (“UVCD”) products for the commercial, military maritime and consumer markets.