Large building spaces (such as hospital waiting halls, shopping malls, subway hubs, etc.) are prone to becoming carriers of bacterial and viral transmission due to high population density and complex air circulation. Traditional low-pressure mercury lamps for disinfection have drawbacks such as mercury pollution, delayed startup, and short lifespan (only 5,000–8,000 hours), making them difficult to meet the needs of routine disinfection in modern buildings.
UVC-LED, as a solid-state ultraviolet light source, efficiently destroys microbial DNA/RNA in the 265–275 nm band and offers advantages such as compact structure and no secondary pollution. In recent years, with advancements in AlGaN-based materials and packaging processes, the photoelectric conversion efficiency and output power of UVC-LEDs have significantly improved, making their large-scale application in large buildings an important research direction in the field of building environmental health.
1. Principles and Core Advantages of UVC-LED Air Disinfection Technology
1.1 Sterilization Mechanism
UVC-LED emits deep ultraviolet light in the 200–280 nm range through AlGaN-based semiconductor materials, which highly matches the peak absorption wavelength of microbial DNA (265 nm), triggering thymine dimer formation and blocking microbial replication.
Experiments show that, under the same irradiation dose, 270 nm UVC-LED has an inactivation efficiency against Escherichia coli (E. coli) approximately 10%–15% higher than traditional 254 nm mercury lamps. Regarding SARS-CoV-2, studies have confirmed that 270 nm UVC-LED exhibits similarly high inactivation capabilities against coronaviruses, achieving >99.9% inactivation in seconds.
1.2 Core Technological Advantages
Compared to traditional disinfection technologies, UVC-LED systems offer multi-dimensional advantages:
Environmental Safety: Mercury-free composition complies with requirements for controlled new pollutants; no ozone release during operation, avoiding chemical residue risks.
Energy Efficiency Optimization: As of 2025, UVC-LED photoelectric conversion efficiency has reached 6%–9%, a significant improvement from 2020 levels (about 3%–5%). Combined with intelligent on/off control, overall system energy consumption can be 30%–40% lower than mercury lamps.
Long-Term Stability: Electrode-free design and advanced thermal management enable UVC-LED modules to achieve lifespans of 15,000–20,000 hours (L70 standard); some high-end products claim up to 50,000 hours, though real-world verification is still needed.
Design Flexibility: Modular structure facilitates integration into air conditioning ducts, ceilings, elevator shafts, etc., without requiring large-scale building modifications.
2. System Design and Application Cases in Large Building Spaces
2.1 Key Points in System Integration Design
UVC-LED systems in large buildings must meet three core requirements:
Airflow Coordination Design: In central air conditioning AHUs (air handling units), place UVC-LED modules after primary filters and before cooling coils, using low-air-resistance quartz sleeve designs to ensure 6–8 air changes per hour.
Irradiation Uniformity Control: Through high-reflectivity (>85%) aluminum reflective cavities and multi-point array layouts, combined with ray tracing simulations (e.g., TracePro or LightTools), the illuminance variation coefficient can be controlled within 20%.
Safety Interlock Mechanisms: Integrate millimeter-wave radar or infrared human presence sensors with response times ≤50 ms to automatically shut off ultraviolet output when personnel enter, complying with GB/T 42596-2023 Safety and Performance Requirements for Ultraviolet Disinfection Lamps.
2.2 Typical Scenario Application Cases
Medical Buildings: A tertiary hospital in Beijing deployed upper-air UVC-LED fixtures in its outpatient hall, maintaining total bacterial colonies below 300 CFU/m³, meeting Class II environmental standards in Technical Code for Hospital Clean Surgery Department Construction (GB 50333-2013). Similar cases exist at Ruijin Hospital in Shanghai.
Commercial Complexes: A shopping center in Shenzhen integrated UVC-LED modules into air conditioning ducts in its food court area; third-party testing (SGS report No.: SZ2024-UV089) showed a natural bacterial kill log value ≥1.0 (equivalent to ≥90% inactivation rate), with airborne microbial concentrations dropping 40%–50% during peak hours.
Transportation Hubs: A transfer station in Guangzhou Metro piloted UVC-LED systems in escalator shafts, achieving >85% removal rate for Staphylococcus aureus.
3. Disinfection Performance Verification
Multiple empirical studies confirm the broad-spectrum bactericidal effects of UVC-LED systems:
278 nm UVC-LED at 25 cm distance and 5 s exposure achieved kill log values >3.0 for Pseudomonas aeruginosa and Candida albicans.
A two-year controlled trial in nursing homes showed that UVC-LED equipment reduced respiratory infection rates by 12.2%.
4. Conclusion
UVC-LED air disinfection systems, with their efficient, environmentally friendly, and intelligent technical characteristics, have achieved large-scale applications in medical, commercial, transportation, and other large building spaces. Empirical data indicate reductions in airborne bacterial colonies of 50%–70% and respiratory infection risks by about 12%, with full lifecycle costs 30%–40% lower than traditional mercury lamp systems. With chip costs expected to drop 30%–40% after 2026 and maturation of intelligent control technologies, UVC-LED is poised to become a core technology solution for air safety prevention and control in large buildings.
