UV Lights – Pros & Cons

Shortly after electrostatic (electronic) air cleaners were developed, furnace manufactures started pushing the use of ultra violet lights in air ducts. The concept is great! Kill the harmful bacteria and viruses in the air stream. It is still recommended today to install a UV light above the air conditioning evaporating coil due to it being a mold haven. The idea behind this is to prevent mold from ever growing on the coil and keeping it in a “like-new” condition for years after install. It’s true, too. Randazzo often removes coils from older homes that have had UV lights installed and maintained for years and the coil looks brand new.
Some of the “cons” of the use of ultra violet light in a heating and cooling system are that the UV lights are so powerful that they can actually breakdown and disintegrate the plastic that is found in most coils that act as a drain pan for condensation or even the plastic that some humidifiers are made of. The UV light can actually make the plastic so brittle it has the same consistency of a potato chip.
The other negative part of some ultra violet lights in a furnace or air handler is that certain lights can create ozone production. Ozone is a know lung irritant and can have negative affects on humans when it is trapped in the home and in your lungs. This is especially bad for people with asthma. One might think that with asthma you would want to use a UV light for clean air. This is true, but that ozone will have worse effects over time, and they will be very hard for a doctor or the patient to detect the source. Lennox manufactures UV lights that do not produce ozone. They use UVA instead of harmful UVB. Lennox coil and humidifiers are also rated to withstand the powerful light the UV lights produce.