Hospitals and health care facilities have been using UV light for years to keep instruments sterile and to kill germs, but using ultraviolet lights in hvac ductwork to improve indoor air quality is still a relatively new concept — especially when it comes to residential applications. However, it may be an idea whose time has come.

Dust Free Inc., Royse City, TX, began seriously working on UV lights as an IAQ enhancement in 1997, according to Greg Burnett. But the company had many questions about how safe and effective this technology would be for treating indoor air, and it didn’t want to forge ahead without sound answers.

Enter Amtec Mechanical, of Tarpon Springs, FL. Amtec’s Jeremy Lowe said his company frequently serves as a testing ground for manufacturers’ new products.

Lowe, who has a solid background in IAQ himself, said that from the start he would refuse to back any product or manufacturer that was touting UV lighting as a cure-all for IAQ problems — because it’s not. UV light has no effect on plain old dirt and dust that might be found in a building’s air ducts. Nor does it have any effect on VOCs from chemicals that are given off by building products such as chipboard, wafer board, carpeting, etc.

But UV light, according to some, can kill airborne micro-organisms and microbes that contribute to mold growth and disease.

Dead or alive

Many air cleaners are efficient enough to capture many molds and bacteria. But the microorganisms remain alive, continuing to grow and reproduce directly on the filtration media.

Placing a UV light close to the air conditioning coil can prevent microbes from breeding in this typically moist area, keeping the coil clean and preventing that yeasty odor that accompanies the growth of these microorganisms.

The goal was to provide a whole house solution, not one limited to just a single room or area. Placement of the lighting, how much to use, and the power level have to be determined in order for this technology to be most effective.

Amtec, under the direction of Danny and Kathy Carbaugh, has 18,000 customers in its active database, giving it a readily available test bed for introducing new products. For this particular product, it went a step further, beyond the usual print advertising and mailing. It began with buying a stock of culture dishes. Techs were encouraged to take the samplers home to see what their own air quality was like. What they found amazed them, and helped give them extra knowledge and enthusiasm for selling this product.

Lowe cautions that use of a culture dish doesn’t automatically mean there are indoor air problems. Microbes are present everywhere, and aren’t normally considered harmful. But the quantity can be an indicator of problems, and certain harmful spores, such as aspergillus and stachybotrys, can also red-flag some more serious IAQ problems.

Cost of installing a UV system can range upwards from about $1,200, depending on how complete the system is. But some customers aren’t dismayed by the cost when they consider the benefits, Lowe said.

Many consider add-ons that bring the cost of a complete system up to $5,000 or so.

The system has been so successful that Amtec has opened its doors as a training ground for other contractors.