Do UV Lights Really Make Indoor Air Quality Better?

Protecting the world from infectious disease

Do UV lights really make indoor air quality better?

There has been a lot of debate over whether UV lighting technology is beneficial to indoor air quality (IAQ); the answer is yes! UV lights can contribute to better indoor air quality. Ultraviolet germicidal irradiation (UVGI) has been used in hospitals for more than 70 years to eliminate airborne pathogens. Since the onset of the COVID-19 pandemic, it has been quickly gaining traction to improve health and safety in offices, schools, restaurants, and other indoor spaces.

uv lights improving indoor air quality

What is UVGI?

Ultraviolet germicidal irradiation uses short-wave ultraviolet energy (UVC) to inactive viral, bacterial, and fungal organisms. It is commonly used as an engineering control in healthcare settings to prevent the transmission of certain pathogens, including tuberculosis, influenza viruses, and mold.

Does UVC Light Kill Viruses?

Research has established that the most effective wavelength range for inactivating microorganisms is between 220 and 280 nm, with 265nm proving to be the most effective. Depending on the dosage, UVGI can damage microorganism DNA, which prevents them from reproducing and spreading through the air.

UVC Benefits in HVAC Systems

Treating your air handling system using ultraviolet germicidal irradiation helps keep the coils, drain pans, and wet surfaces of your systems clear of microbial growth. Without UVC lights in place, coils become clogged and insulated with a matrix of dirt, bacteria, mold, and viruses called biofilm. A biofilm of only .02″ can reduce system efficiency by 22-37%. As a result, your equipment works harder, wasting energy and increasing your energy costs. 

Properly sized UVC lights can eliminate viruses, mold, bacteria, and other contaminants, increase system efficiency, and turn your HVAC system into a powerful disinfection tool to improve indoor air quality and building health.

UVC lights can also reduce your maintenance costs by keeping your HVAC coils clean, therefore eliminating the need for routine coil cleaning.
Industry case studies show that coils treated with UVC had an increased pressure drop compared to coils that were manually cleaned. 

UVC ROI in HVAC Systems

The cleaning action of UVC lamps on fouled coils is so effective that the retrofit of a UVGI system for cooling coil cleaning will typically pay for itself in 2 to 3 years thanks to the significant savings in energy and maintenance costs. 

The energy savings result from two effects – reduced pressure loss through the coils once the fouling is removed, and increased rate of heat transfer in the coils when the fouling film is gone.

Incentives for Energy Efficient Upgrades in Commercial Buildings

EPACT 179D: A tax deduction of $1.80 per square foot is available to building owners who install heating, cooling, or ventilation systems that reduce the energy and power cost of HVAC systems by 50% or more in comparison to a building meeting minimum requirements set by ASHRAE Standard 90.1. Offices, retail stores, warehouses, and public buildings are eligible for this deduction.

Implementing UVC lamps into air handling units for surface disinfection of cooling coils can also help building owners and their facilities management teams qualify meet the requirements detailed in many internationally recognized building standards programs, such as the WELL Building Standard. Such certifications can help attract and retain talent, maximize employee productivity, and promote health and wellbeing to all of your customers and employees.

UVC Disinfection Systems & HVAC Design

While UVGI in HVAC systems is a powerful approach to improving IAQ, building owners must consider the design of their HVAC system to consider life cycle costs and any potential impacts of design solutions on future occupants. 

Germicidal ultraviolet light at 254 nm is the most effective in inactivating pathogens, but if the temperature where the UVGI system is installed is too high or too low, it can decrease the microorganisms’ susceptibility to ultraviolet germicidal irradiation.

Similarly, if UVGI systems are installed in an air handling unit or duct, relative humidity should be controlled to 40–60% for optimal efficiency. High humidity conditions may require increased UV irradiation levels to achieve equivalent effectiveness. 

The best way for building stakeholders to ensure they are following best practices with UVGI is to monitor and measure the conditions, and provide the proof that their UVGI systems are working correctly. 

Protect your indoor environment and get more from your investment when you partner with Safe Air Systems Technology. We’ll collaborate with your organization to create and provide a comprehensive indoor air quality policy that is supported by site-specific indoor air quality management plans, antimicrobial technology recommendations, indoor air quality sensor technology, data analytics, multiple dashboard views, and annual reassessments to ensure that your facility remains in compliance with the strictest federal, state, and local standards.