Hospital Grade Disinfection Options

Achieving Hospital-Grade Air Disinfection without Sacrificing Sustainability

Prior to the Covid-19 pandemic, many of us were familiar with hand washing and disinfecting wipes, but less familiar with effective mitigation strategies for airborne diseases. Fortunately, we have significantly improved our understanding of the importance of indoor air quality and the role clean air plays in keeping us safe from airborne pathogens. Hospitals have known this for decades and have to meet stringent indoor air quality (IAQ) codes that are often 3-7x higher than non-healthcare settings. To meet these elevated standards, they use powerful and expensive HVAC systems and are hit with hefty electric bills each month.

So, is it practical for schools, offices, and other non-healthcare settings to achieve such lofty standards? One approach that is gaining traction is upper-room ultraviolet germicidal irradiation (UR-UVGI). This technology, with nearly a century’s worth of evidence supporting it, was used successfully to prevent measles in the 1930s, tuberculosis in the 1950s, and has now reemerged as SARS-CoV-2 is also airborne. In this article, we will take a look at the traditional approaches to ventilation and filtration, and explore how upper-room UVGI can be used to achieve hospital-grade air disinfection sustainably.

Covid-19 pandemic brought about unprecedented awareness of the importance of sustainable indoor air quality

The outbreak of Covid-19 has resulted in a greater understanding of how airborne viruses can spread. This has led to a heightened awareness of the importance of indoor air quality in preventing the spread of disease.

At the beginning we all learned about social distancing and masking. Some of us, certainly facilities managers, learned about the ability to reduce viral exposure via ventilation and filtration. Experts from government and academia have recommended higher ventilation as a primary means to mitigating the spread of current infectious disease and preventing future outbreaks. What matters for ventilation when it comes to infection prevention is supplying more clean air faster. A simple metric to measure this is air changes per hour (ACH), which measures the number of times per hour the air in a room is replaced with disinfected air. For most non-healthcare buildings, minimum ventilation rates range from 1-3 ACH. 

Experts from government and academia have recommended higher ACH as means to mitigating the spread of current infectious diseases (flu, norovirus, and others) as well as preventing future pandemic outbreaks. The question is whether businesses, schools, and regulators will listen to the recommendations.

There will be a new normal for IAQ

While the pandemic is not the all-encompassing worry it once was, many behavioral and building changes catalyzed by the pandemic are sticking. For example, we’ve seen widespread adoption of IAQ monitors as well as upgrading MERV filters. And workers are still demanding healthier buildings from their employers.

More importantly though, ASHRAE, the standard setting body for buildings, has committed to developing a new standard for pathogen mitigation. When this happens, IAQ will no longer be a nice-to-have, or a right-to-have, but a must-have. This new standard will have far-reaching benefits for all building occupants and significant implications for the commercial real estate sector.

One immediate implication is that building managers will need to respond to the demands of occupants who will be able to point to new building standards as the new normal. To satisfy employees or retain tenants at market rates, owners will need to determine how they will comply.

This will not just be a U.S. phenomenon. ASHRAE is a global organization with members in over 130 countries. Additionally, Belgium has already enacted legislation establishing stricter IAQ requirements for public venues. In the U.K., a government-commissioned report by the leading engineering bodies called for enforceable clean-air regulations. 

Let’s take a look at the traditional approaches of ventilation and filtration

In the most basic sense, ventilation is supplying clean air to a space and removing contaminated air. Filtration is removing undesirable particles from air. Note that despite early recommendations to upgrade HVAC filters to MERV 13 or higher, leading experts (including CDC and ASHRAE) have provided guidance that MERV filters (and in-duct UV) are unnecessary and ineffective approaches to reducing the spread of Covid-19 as it’s primarily transmitted in-room rather than across rooms (via ventilation ducts).

There is a consensus that increasing ventilation is an effective approach to mitigate viral spread. While there are a number of barriers that prevent organizations from taking this step, we’ll focus on the increased energy consumption and greenhouse gas (GHG) emissions.  

In the U.S., HVAC systems account for nearly 16% of all greenhouse gas emissions and 40% of emissions from buildings. The reason they consume so much energy is not just from moving air, but treating air as well. HVAC systems continuously bring in outdoor air that needs to meet the specifications for comfort and health. These energy-intensive processes include moving, heating, cooling, filtering, and dehumidifying (or humidifying) air.

A study performed by AESC modeled the additional energy and GHG emissions required to meet the recommendations ASHRAE provided to reduce viral transmission of Covid-19, including enhanced ventilation and filtration. They found a median 45% increase in energy and emissions across 6 cities and 2 building types. 

While a 45% increase in greenhouse gas emissions is untenable for many sustainability-conscious organizations, a 45% increase in energy costs is a non-starter for most organizations facing rising interest rates and uncertain economic conditions. Fortunately, there is an energy-efficient and climate-friendly way to achieve enhanced air disinfection that doesn’t require moving and treating large amounts of air.

Upper-room UVGI is a recognized approach that is vastly more energy efficient

Upper-room UVGI is a widely-recognized approach to reducing exposure to harmful microorganisms because of its well-documented history of preventing the spread of TB and measles. It works by inactivating microbes in the air by exposing them to germicidal UV-C light in the upper portion of an occupied room. R-Zero’s upper-room UVGI device, Beam, consumes about as much power as a high-quality laptop. Just one Beam is powerful enough to protect an entire classroom or large conference room.

beam diagram

Additionally, UV-C devices can be targeted to the highly-occupied spaces where people face the greatest risk of exposure to infectious pathogens. Accordingly, upper-room UVGI requires 94% less energy and GHG emissions than using HVAC. UR-UVGI makes providing healthy indoor air for your employees, students, patients, and residents the cost-effective and sustainable choice.

What does this mean for you and your sustainability goals?

A new and elevated standard is coming as part of the healthy buildings movement – both in the form of occupant demand as well as in building codes. How building managers choose to meet this new standard will have a significant impact on their energy costs and healthy building sustainability goals. The evidence for upper-room UVGI is clear – it’s both highly effective and energy-efficient.

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