Germicidal UV Light RESEARCH for UV Light Disinfection

To learn more about UV light disinfection as it relates to devices for commercial and industrial properties see: Germicidal UV Light

UV Light Disinfection: Ultraviolet lights were shown to KILL MOLD, VIRUSES and BACTERIA more than 100 years ago. In 1903, Niels Finsen was given the Noble Prize in Medicine for using UV to effectively treat patients with skin infections.

Today, UV lights are used for germicidal use in hospitals, restaurants and grocery stores. Germicidal UV light has been shown effective in killing sterilizing an HVAC system. Here are two examples:

1). Germicidal UV light study: In 2012, a study at Duke University Medical Center showed that UV lights killed 97% of bacteria that were resistant to antibiotics, the so-called superbug bacteria that are the toughest to kill.

2). Germicidal UV light study: The Journal of Applied and Environmental Biology reported in 2001 that germicidal UV radiation significantly reduces airborne fungi in air handling units.

Germicidal UV light study:  Options for your HVAC System

There are basically two types of UV lights as options for sanitizing HVAC systems. They have various names including purifying lights, germicidal lights, sanitizing lights and sterilization lights.
Coil Sanitizing Lights:

This application has been used mostly for single family residences to date: If you have central air conditioning, then you have an indoor coil. It is a prime location for the development of mold and bacteria. Why?

Because the coil is used to condense moisture from the air to dehumidify homes during AC cycles. As air passes over the coil, dirt, pet dander and other debris stick to its wet surface. The combination creates an ideal setting for the growth of mold and bacteria that can be spread through your home in the passing air. Coil UV lights are the most common HVAC sterilizing lights. Single-lamp and dual-lamp models are produced. Coil sterilization lights are installed where they can shine directly onto the surface of the coil, and they are left on continuously.

Air Sanitizing Lights:

This type of HVAC germicidal lights are installed in the ductwork bringing return air to the system. Their purpose is to kill airborne germs and mold. Stick and U-shaped lamps are used by various manufacturers. Some air germicidal HVAC lights are coordinated with the blower motor to turn on and off as it does. These must be hardwired with the system, so installation cost is on the high end of the spectrum.

Additional Research on Germicidal UV Light:

UV Light Disinfection: How do UV-Light Air Purifiers Work?  https://molekule.science/how-do-uv-light-air-purifiers-work/

UV Light Disinfection: How UV light is Used in Air Purification  https://www.oransi.com/page/uv-light

UV Light Disinfection: How Ultraviolet (UV) Light Improves Air Quality and Well-Being https://www.servicechampions.net/blog/ultraviolet-uv-light-air-quality/

UV Light Disinfection: Using Ultraviolet Germicidal Light for Air Cleaning  https://iaqscience.lbl.gov/air-uv

UV Light Disinfection: Ionizer and UV Lights: Potentially dangerous tech in your air purifier  https://www.toptenreviews.com/ionizers-and-uv-lights-potentially-dangerous-tech-in-your-air-purifier

UV Light Disinfection: The Best UV Lights for HVAC – 2020 Buyer’s Guide  https://hvactraining101.com/best-hvac-uv-lights/

UV Light Disinfection: Top 5 Best Rated UV Lights For HVAC (**2020 Review**)  https://homeinspectorsecrets.com/hvac-uv-lights/best-hvac-uv-light/

UV Light Disinfection: Do HVAC UV Lights Improve Indoor Air Quality?  https://www.angieslist.com/articles/do-hvac-uv-lights-improve-indoor-air-quality.htm

UV Light Disinfection: UV Lights for HVAC Systems? Worth the money? https://www.pickhvac.com/faq/hvac-uv-lights/

UV Light Disinfection: Best UV Lights for HVAC – (Reviews & Buying Guide 2020)  https://www.homeair.org/best-uv-light-for-hvac-reviews/

Duke Medicine study on Germicidal UV light study:

The study was sponsored by the CDC Prevention Epicenters Program (U54CK000164).

https://medicine.duke.edu/medicinenews/cleaning-hospital-rooms-chemicals-uv-rays-cuts-superbug-transmissions

Cleaning Hospital Rooms With Chemicals, UV Rays Cuts Superbug Transmissions

Wednesday, October 7, 2015

UV light disinfection

A new study from Duke Medicine has found that using a combination of chemicals and UV light to clean patient rooms cut transmission of four major superbugs by a cumulative 30 percent among a specific group of patients — those who stay overnight in a room where someone with a known positive culture or infection of a drug-resistant organism had previously been treated.

This group of patients represented about five percent of more than 600,000 patients across the study hospitals. Duke researchers will present the findings in San Diego on Friday, Oct. 9, at ID Week, an annual meeting of infectious disease experts from around the world.

The randomized trial was conducted at nine hospitals in the Southeast from 2012 to 2014, including three Duke University Health System hospitals, a Veterans Affairs hospital, and several smaller community healthcare centers. The trial studied how three cleaning methods affected the transmission of four drug-resistant pathogens: MRSA, vancomycin-resistant enterococci (VRE), C. difficile and Acinetobacter.

“Some of these germs are hardy and can live on the environment long enough that even after a patient with the organism has left the room and it has been cleaned, the next patient in the room could potentially be exposed,” said Deverick J. Anderson, MD, associate professor of medicine (Infectious Diseases) and lead investigator of the study. “Several groups have demonstrated that enhanced cleaning strategies such as using portable UV machines can kill these germs, but this is the first well controlled study that shows these techniques can make meaningful difference in patient outcomes.”

The standard approach for room cleaning involves the use of a quaternary ammonium disinfectant, or “quat.” Participating hospitals used three methods for killing the germs: irradiating the room with UV after using a quat, replacing the quat with bleach, and replacing the quat with bleach and irradiating the room with UV light. The researchers found that the most effective strategy was to proceed with standard disinfection quats, followed by a 30 to 50 minute cycle with a portable UV irradiating machine.

“The staff would open drawers, open doors to the bathroom, roll the machine into the center of the room,” Anderson said. “UV light works through reflective properties, killing organisms even in the shadows if there is space for light to reflect. The light disrupts the DNA of these germs and kills them.”

In the specific subgroup of patients who were studied, the method resulted in an almost one-third cumulative reduction in acquiring any of the four superbugs or developing infections in the following three months, the researchers found.

“This study provides strong evidence that enhanced environmental cleaning can help reduce transmission of dangerous germs to a specific group of at-risk patients”, said John A. Jernigan, MD, an expert on healthcare-associated infections with the Centers for Disease Control and Prevention (CDC). “The findings represent an important step forward in understanding the role the hospital environment plays in transmitting infection, but we still have a lot to learn about the impact this specific type of intervention will have for the entire population of hospitalized patients.”

In addition to Anderson, study authors include Luke F. Chen; David J. Weber; Rebekah W. Moehring; Sarah S. Lewis; Patricia Triplett; Michael Blocker; Paul Becherer; J. Conrad Schwab; Lauren P. Knelson; Yuliya Lokhnygina; William Rutala; and Daniel J. Sexton.

The study was sponsored by the CDC Prevention Epicenters Program (U54CK000164). The study authors also disclosed relationships with UpToDate, Online, and Clorox, Inc.

Picture: During the trial, a Tru-D SmartUVC machine was used in combination with chemical agents to disinfect patient rooms. Shawn Rocco/ Duke Medicine