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Boost HVAC Efficiency and Air Quality with UV C Disinfection Technology
Learn how monitoring UV C disinfection for HVAC efficiency/energy savings can enhance performance and reduce energy costs in your system.
Ultraviolet light has been used since the 1990s to enhance HVAC efficiency, improve air quality, and reduce energy consumption. Germicidal UV technology has attracted attention since researchers demonstrated that UV C can reduce airborne pathogens in occupied spaces. In 1937, epidemiologist William F. Wells installed UV lamps in Philadelphia schools and lowered measles infection rates to 14.5 percent compared to 55.3 percent in schools without UV C.
This article explores the benefits of UV disinfection technologies—including traditional UV C (254 nm), UV C LEDs, and Far-UV (222 nm)—in HVAC air handling units (AHUs). It further examines how linking UV monitoring systems with Building Automation Systems (BAS) or Building Management Systems (BMS) provides real-time oversight that boosts both efficiency and operational savings.
The Benefits of UV C in HVAC Air Handlers
1. Improved Indoor Air Quality (IAQ):
UV C technology is well established for its ability to inactivate airborne microorganisms, including bacteria, viruses, and fungi. Installing UV lamps within AHUs or near ceilings in occupied spaces effectively neutralizes these contaminants, reducing the risk of airborne disease transmission.
ASHRAE recognizes that UV C can inactivate up to 90 percent of microorganisms residing on HVAC surfaces, depending on factors such as UV C intensity, exposure time, and environmental conditions. The U.S. Centers for Disease Control and Prevention also recommends UV C and mechanical HVAC filtration as two primary technologies that can “improve air cleanliness in the workplace.”
2. Reduction of Biofilm and Mold Growth:
The dark, moist environment of an HVAC AHU is an ideal breeding ground for mold and biofilm accumulation on cooling coils and drain pans. Microbial and biofilm growth on HVAC components can lead to coil fouling, forcing operators to compensate for the loss in cooling capacity by lowering chiller temperatures, pumping more chilled water, and/or boosting fan speed. Each of these adjustments results in higher energy consumption and operational costs.
The buildup of organic contaminants obstructs efficient heat transfer by creating an insulating layer on the coil, preventing warm air from effectively exchanging its heat with the coil. Installing UV C lamps downstream of the cooling coil limits microbial growth, reducing pressure drops and allowing for optimal heat exchange.
3. Energy Efficiency and Cost Savings:
A cleaner HVAC system operates more efficiently. When biofilm and mold are unchecked, they insulate cooling coils and force fans and compressors to work harder, increasing energy consumption. Studies show that UV C systems can improve coil efficiency by as much as 10-20 percent, translating to lower energy bills and extended equipment life. Cleaner coils also generate labor savings, as mechanical cleanings or pressure washing tasks are eliminated.
Linking UV Monitoring to BAS/BMS for Optimal Performance
Monitoring UV intensity and performance is crucial to maximizing the effectiveness of UV C systems. By integrating UV monitoring systems with BAS/BMS, facility managers can gain real-time insights into system operation and optimize performance.
1. Real-Time Performance Monitoring:
UV intensity degrades over time, and lamps need periodic replacement to maintain effectiveness. A UV monitoring system integrated into a BAS/BMS allows facility managers to track lamp intensity and receive alerts when levels drop below optimal ranges. This ensures that the UV C system is continually operating at peak performance.
2. Predictive Maintenance and Automated Alerts:
Instead of relying on scheduled maintenance checks, BAS/BMS-integrated UV monitoring enables predictive maintenance. Facility managers can receive automated alerts when a UV lamp is nearing the end of its lifecycle, reducing the risk of system downtime and ensuring that maintenance is performed only when necessary.
3. Comprehensive Monitoring:
Some UV monitors are equipped with sensors specifically configured for the traditional UV C (254 nm), UV C LED, and the emerging Far-UV (222 nm) UV C wavelengths, ensuring accurate lamp performance detection across the entire spectrum.
Optimizing Indoor Air Quality and HVAC Efficiency Through Advanced Technology
Integrating UV C disinfection technology within HVAC air handlers is a game-changer for IAQ, energy efficiency, and equipment longevity. When coupled with UV monitoring systems and linked to BAS/BMS, facility managers can enhance system performance through real-time monitoring, predictive maintenance, and energy optimization. As the demand for clean and efficient air-handling solutions grows, HVAC professionals should advocate for these advanced integrations to provide healthier indoor environments while maximizing operational savings.
The president and founder of Aerapy UV Disinfection Technology, Annette Uda, is an ASHRAE Member and a corresponding member of the ASHRAE Technical Committee 2.9 and ASHRAE SPC-185.5, devoted to Ultraviolet Air and Surface Treatment. She may be reached at auda@aerapy.com
[1] Wells, W. F. and Wells, M. W. and Wilder, T. S., The Environmental Control of Epidemic Contagion. I. An Epidemiologic Study of Radiant Disinfection of Air in Day Schools. Table 16 (1942). American Journal of Hygiene, (97–121). https://ghdcenter.hms.harvard.edu/files/ghd_dubai/files/wells_1942.pdf
[1] ASHRAE. (2024). ASHRAE position document on filtration and air cleaning. ASHRAE Technology Council. https://www.ashrae.org/File percent20Library/About/Position percent20Documents/Filtration-and-Air-Cleaning-PD-2024.PDF
[1] CDC. Improving Air Cleanliness. Mitigation Strategies Webpage. 2024. P.2. https://www.cdc.gov/niosh/ventilation/prevention/air-cleanliness.html
