Cleveland HVAC Blog

Reducing Mold with Ultraviolet Lights

Posted by Paul Wadsworth on Tue, Aug 24, 2010 @ 09:14 AM

Ultraviolet lights or light sticks can reduce the mold, bacteria and other allergens that infiltrate your duct work. These allergens are a serious problem for many, and regular exposure to them can increase a person’s risk for developing serious respiratory conditions.

What is the principle behind ultraviolet lights? The EPA recommends three proven ways to improve air quality: source control, ventilation, and filtration.

UV lights treat air at the source to reduce and kill mold. They do this by using light waves measuring between 200-280 nanometers, invisible to the human eye.  Hospitals, water treatment plants, and restaurants have used ultraviolet lights for years to sanitize air, water, and surfaces.

UV lights work by penetrating a mold cell’s DNA. The high-intensity light waves permanently damage the DNA code – effectively sterilizing the cell and making it unable to divide and reproduce.

The amount of ultraviolet light required to kill mold or bacteria is a calculation of UV Intensity x Exposure Time. This is known as the lethal dosage. Each particular pathogen has a specific lethal dosage, so it is good to check the specifications of any light before installation.

The intensity of the UV radiation is the most important factor to consider when buying a light. Because airborne mold and bacteria are in range for a very limited time, the light must work fast. The rate at which the light reduces and kills mold and bacteria is the kill rate. The kill rate is affected by these three factors:

  • Lifespan: typically a light lasts for around 8,000 hours.
  • Wind chill: the colder the glass, the more difficult it is for the ultraviolet light to penetrate.
  • Maintenance and installation: both dust on the outside of the light and mercury buildup inside reduce UV output. Proper positioning also increases the effectiveness of the light.

However, when properly installed and maintained, ultraviolet technology can greatly reduce mold in your air handler. If you have an A-frame coil in your air handler, it is relatively easy to install a UV light stick running parallel with the coils.

Always make sure to follow the manufacturer’s instructions when installing, working on or when you are around exposed UV light.  Remember to give the light a final wipe with a clean dry rag before sealing it into the cabinet, and place a sticker on the air handler to remind yourself to change the bulb every year. Install the light’s ballast in the control panel box or other dry area to protect it from excess moisture. Of course, if you’re worried about the wiring, don’t hesitate to contact us to install it.

P.K. Wadsworth services the Greater Cleveland, OH area including cities Chagrin Falls, Shaker Heights, Eastlake or anywhere in between.  To get started, check out our website.

Topics: uv radiation., ultraviolet technology, uv lights, high intensity light, ways to improve air quality

About the P.K. Wadsworth Blog

Welcome! Read our latest posts or explore the archives. You’ll find tips for how to maintain your HVAC equipment to discussions about indoor air quality, conserving energy and saving money, and information about emerging technologies in heating and air conditioning. Bookmark our blog.

Check for new posts regularly.

Subscribe to Email Updates

Posts by Topic

see all