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Ozone, Germicidal UV, and More - OH MY!

UV Light in Duct

Ozone :

 

To get the benefits of ozone without creating harmful byproducts or overproducing ozone in a breathing space, we do a duct mounted application. We use a small 5” adjustable ozone lamp for residential and light commercial applications where most, if not all, of the ozone is used up in the oxidation process inside the ducts. We wholeheartedly agree with the EPA’s and OSHA’s stance on room occupied ozone generators and safe limits. We also abide by Section 3.2 of ASHRAE Position Document on Filtration and Air Cleaning that ozone units should not be used in occupied spaces.

 

Once again, putting ozone directly into the breathing space can be a potential health risk and should only be used for smoke, mold and mildew remediation caused by some type of water damage, flooding, or fire - after the building is evacuated for this purpose. These in-space ozone units are also used in hospital applications and hotels to sterilize patient rooms and to get rid of smoke odors in guest rooms. Once again, in both of these examples the room is unoccupied during this process.

 

Our units utilize this 5” ozone lamp yet does not create enough ozone to be effective in the aforementioned applications. It does create low levels of ozone inside the ducts to freshen the air by oxidizing gasses and odors inside the ducts as they pass by the ozone unit. When designing and engineering our residential in-duct UV ozone generating units, careful testing and monitoring of the indoor ozone levels were conducted following EPA and ASHRAE protocol and to abide by their standards.

 

Germicidal UVC:

 

To understand how UVC works, you have to get your science goggles on and go back to the time of Bill Nye in the portable classroom TV.

 

Ultraviolet energy inactivates viral, bacterial, and fungal organisms so they are unable to replicate and potentially cause disease. Although the entire UV spectrum is capable of inactivating microorganisms, UVC energy (wavelengths of 100 - 280 nm) provides the most germicidal effect. UVA (wavelengths of 315 -400 nm) and UVB (wavelengths of 280 – 315 nm) take much more time and need to be closer to the microorganism than with UVC to inactivate it.

 

ASHRAE states UVC In-Duct air disinfection requires high UV doses to inactivate microorganisms on-the-fly as they pass through the irradiated zone due to the limited exposure time and the minimum target UV dose is 1,500μW•s/cm2 (1,500μJ/cm2). For systems typically designed for a 500-fpm moving airstream, the minimum irradiance zone is two feet and the minimum UV exposure time is 0.25 second.Clean Air Defense System UV systems exceed these requirements with high-output UVC lamps.

 

I know that is a LOT of really sciency terms but to put it in plain english, the UV rays cause the cell membrane to break down so it not only stops replicating, but essentially dies. This keeps it from circulating back into the air you breathe.

 

So, now you know more about IAQ than the average Joe. I hope this not only educated you on the consequences of prolonged exposure to poor IAQ, but also what changes YOU can make to improve your health, this way you have the knowledge and power to make educated choices regarding your IAQ health. If you have any questions or are interested in scheduling an estimate, please don’t hesitate to call our office.




 
  1. https://www.epa.gov/indoor-air-quality-iaq/introduction-indoor-air-quality

  2. https://www.epa.gov/indoor-air-quality-iaq/inside-story-guide-indoor-air-quality#:~:text=EPA's%20Total%20Exposure%20Assessment%20Methodology,rural%20or%20highly%20industrial%20areas.

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