Improving IAQ System Efficiency with UVC LEDs
In the aftermath of the COVID-19 pandemic, there is a heightened awareness of the importance of indoor air quality (IAQ) across public spaces, commercial buildings, and residential homes. This awareness has led to an adjusted global market forecast of almost 240 million by 20281 with a compounded annual growth rate of 6.3% and governments pledging support2. One of the significant trends impacting this growth centers around access to more real-time data on parameters that affect air quality, like humidity, temperature, CO2, TVOCs (Total volatile organic compounds), and particulates. With the ability to better quantify the factors that impact air quality, the focus then moves to advanced filtration and ventilation—and how these factors connect to improve overall building automation, sustainability, and efficiency as well as occupant health3.
Consumers’ amplified attention to airborne infectious pathogens has increased demand for systems with integrated UVC disinfection. Traditionally, this UVC irradiation has been delivered by mercury lamps, providing a potent dose of germicidal UVC at 254 nm. In addition, it has long proven effective at inactivating airborne pathogens.
Although most of the focus has been on treating the air directly, another critical aspect is the internal HVAC system components' condition; for example, in many HVAC systems, condensation forms on cooling coils and creates an ideal environment for microbial growth and the spread of biofilms over the heat-exchange surface. This insulating film can also be responsible for the foul and harmful odors consumers can smell when ventilation is running.
Biofilms significantly reduce the efficiency of the system due to their insulating effect. In fact, according to the US EPA, a biofilm buildup of 0.5 cm can decrease system efficiency by 21%. Biofilms also compound air drag as the surface film traps particulates and forces fans and blower wheels to work harder. According to ASHRAE, this can increase the energy required in the system by 5-20%. Furthermore, it can lead to higher maintenance costs due to microbiologically induced corrosion4. Thus, continuously preventing biofilms ensures the overall health and performance of the system and, in turn, the quality of the air it is meant to condition.
However, traditional UVC sources like mercury lamps have a 360-degree irradiation design and footprint constraints that present challenges in some surface applications. Unlike UVC lamps, germicidal UVC LEDs target these complex surfaces with flexible design configurations and directional point-source of UVC irradiation. In addition, these LEDs deliver the correct UVC dose to maintain the target surface's cleanliness without using baffles or shielding.
UVC LEDs can deliver biofilm prevention using a targeted but sensibly adequate UVC dose continuously for the 15+ years of HVAC equipment life. This low dose reduces the negative impact of excessive UVC irradiation on exposed materials. Further, it lowers the system's potential to form harmful secondary by-products5 in the air through Reactive Oxidative Species (ROS) and Secondary Organic Aerosols (SOA). UVC LEDs ensure that the system does not generate VOCs and particulates that then trigger the IAQ sensors in the emerging building ecosystem while also futureproofing products from mercury restrictions6.
Learn more about how UVC LEDs can safely and effectively prevent biofilms and mold on HVAC surfaces here or by visiting the Crystal IS team at the AHR Expo in booth C5361 .