A Guide for Building Managers to Adopt Germicidal (UV-C) Lighting Solutions

Types of Common UVC Lighting 

·      Low Pressure Mercury Vapor (most common)

·      Hot/Cold Cathode

·      High Intensity Discharge (HID)

LED Lighting (260-280nm) - UVC lighting can come in different types, including LED (solid state lighting). Veteran LED is leading the charge for wide-scale adoption of Germicidal LED’s that include real-time, web-based controls, that help monitor the effectiveness and lifecycle of UVC lighting. IES in partnership with IUVA have reached an agreement to publish ANSI standards by years end (2020) to include an Approved Method for Electrical and Ultraviolet Measurement of Solid-State Sources. UVC LED technology will continue to improve as manufacturing, research, and development is ramped up. Follow the Veteran LED blog for up-to-date information on commercially available UVC LED products and solutions.

Specifications to Consider

·      Power Supply (Ballast/Driver) - Instant or “Rapid” Start, Pre-Heat

·      Voltage Range – Low/High (standard 120-277V +/- 10% or 440/480V)

·      Lifespan Range – 4,000 - 12,000hrs

·      Wavelength Range - 200-280nm (tested effective at 265nm per ASHRAE)

·      Cover Area – Irradiance area

·      Efficacy – Measured at distance intervals

·      Controls – “IoT” Application, System Integration, and/or Build Out 

·      Compliancy – FCC Part 15 Class A, NEMA 4 Rating, UL 153, RoHS, ASHRAE, ANSI, etc.

·      Other Options – Mounting, beam angle, material, housing color

Effectiveness

Quite simply the effectiveness of each solution is based on the percentage of microbial population that is inactivated based on one pass through an irradiance field. Effectiveness depends on a few variables and the calculations may be particularly complex when looking at the numerous types of materials for surface disinfection, but general guidance may be confidently followed with some careful considerations including consulting professionals and published standards. Here is some important data to understand:

·      UV Dose (millijoules per square centimeter) = Irradiance (microwatts per square centimeter) * Exposure Time

·      Distance – From center point of UVC lamp to surface or area of effect

·      ACH – Air changes per hour / Space / Per Person

·      CFM – Volume of Air Flow in cubic feet per minute

·      Temperature – Degrees Fahrenheit or Celsius 

·      Humidity – Increased humidity means an increase in water vapor in the air which can impede the UVC field. General recommendation from ASHRAE is 40-60%

·      Irradiance or Curing Area – mm / in

·      Optic Power – mw/cm2

Applications 

Upper Area Lighting - By placing fixtures with their UVC light directly aimed at the upper area of a room, these fixtures are able to be used 24/7 without harming occupants of the room. This is particularly effective in environments of high traffic, unpredictable occupancy, and high ceilings (over 10ft). This strategy is utilized in conjunction with fans and proper ventilation that helps circulate air upwards into the irradiance zone as frequently as possible.

Common Area Lighting (Unoccupied Rooms ONLY) - For years hospitals and medical facilities across the globe have been using UV-C to help disinfect operating rooms in between operations. The same concept is applied in all other building applications where UV-C area lighting is used intermittently (normally at night in between shifts), for a specified duration, and by operation, would never come in contact with human skin while activated. Particular safety measures via controls would provide two layers of safety to ensure inhabitants would not be subject to the harmful UV rays (motion sensors on fixtures and on doors at entrances to area). An added benefit to this is energy consumption off-peak hours so your only slightly adding to your carbon footprint.

HVAC - Airborne transmission of COVID-19 is believed to be responsible for at least 70% of all cases in the U.S. There is almost a unanimous belief that everyone will think about indoor air quality and the “healthy environment” more and more due to our society’s recent exposure to COVID-19 and the global effect of this pandemic. UVC lighting is often installed in duct systems on the return side and disinfects the air (Ex. @ 2ft distance / @ 400fps) while also reducing the strain on MERV/HEPA filters. UVC can also be installed where the light is directed on the coils to prevent build up, reduce PM costs, and increase the lifespan of the system. Drain pans are often a breeding ground for bacteria where UVC lighting can be effective. 

Disinfecting Chamber – UVC disinfection chambers are useful for disinfecting specific items being carried into and out of facilities. Personal items such as wallets, keys, briefcases, and back packs or packages delivered through a central mail room may be prime candidates for a UVC chamber application in C&I facilities. UVC chambers can be used for curing and disinfecting numerous types of materials. Always consult the MSDS and manufacturer recommendations when assessing exposure time and utilizing safety precautions.

UVC Platforms – In recent years, platforms such as the HealthySolePlus have been developed to attack germs, bacteria, and pathogens brought into a facility through the soles of shoes. Where PPE (“booties”) are not supplied or required, this may very well prove to be another option. 

Handhelds– Wands, flashlights, or “guns” that aim UVC light in a narrow and intense manner need to be used very carefully as to not endanger the operator or materials in which the user is aiming to disinfect. Those not operating this equipment should be far enough away from the irradiance zone to refrain from any UVC light exposure. These items may present a false impression of disinfection and are often used improperly, particularly around exposure time and distance.  

Robotics – In recent years there have been technological breakthroughs surrounding the use of robotics (in conjunction with AI, IoT, machine learning) and UVC lighting applications. Most of these UVC lighting robotic companies have been focused on healthcare associated infections (HAI’s), but as a result of COVID-19 we are seeing an increase in demand in numerous market sectors including office buildings and even prisons. Fully autonomous and semi-autonomous products are available with a wide range of capability. It is important to understand this difference when calculating cost, O&M expense, custom design, and set-up time.

For more information on Germicidal Ultraviolet Lighting solutions, please contact Veteran LED at 804-562-8606 or visit us online at www.VLED.energy