Looking into an air filtration system for my home HVAC. One guy wanted to sell me on a UV air cleanser that they install in your existing furnace. Hard to find any real info on their effectiveness. Do they do what they claim to do? That is, kill airborn microbes and make your indoor air quality that much better?
UV lights are regularly used in the ductworks in hospital operating rooms to help maintain sterile environments.
My personal opinion is that they would help some, but I don’t think I would need such a device; live and love your germs.
I reviewed a report on different air cleaning technologies as it pertained to reducing bacteria and other aerosolized toxins in commercial buildings. The upshot of the report was that even for the technologies that removed 99+% of the material going through the filter, the concentration of the contaminant in the air in the occupied spaces was maybe 50% at best (this is off the top of my head).
It depends a lot on how the space is used and the turnover rate of the air conditioning system. If you have a lot of people kicking up dust and bacteria off the carpet and the HVAC is only on like 10% of the time it will be a lot less effective than for an unoccupied space with continuous turnover.
I think UV can help reduce infectious materials but I don’t think it’s that effective.
UV of short enough wavelength, like the 183 nm line of Mercury, turns some oxygen into ozone. Ozone is a very corrosive and poisonous gas that does have good disinfection performance. In hospitals, they do, or at least used to, put such UV lamps into ducts to create the ozone. It is much like adding ozone to water to sterilize it for municipal systems.
UV of somewhat longer wavelength, like the 254 nm line of Mercury, turns ozone back into oxygen. I wonder if there are systems with 183 line lamps upstream and 254 line lamps at the outlets, to keep the system sterile.
Hi Filmyak,
As someone who works in the ozone industry – and I’d give pretty low odds that the company trying to sell you the UV light and the company I work for are one in the same – there is value in the service, at least the heads of our company absolutely believe so. I’m mere admin support (and new to the company), not a salesperson or technician, so far from an expert, but have glanced through enough reports (some unbiased, some not) trumpeting the disinfecting/deodorizing power of ozone (created from oxygen molecules through the use of UV lamps). I do believe it’s legit.
As for its necessity, I think it depends on the situation. The need to disinfect against germs is obviously necessary in hospitals and the like, although I can’t say for its needs in someone’s home; there’ seems to be a need for germs in our environment to give our immune systems the opportunity to “flex their muscles” in preparation for a legitimate attack. That said, to remove smells, whether it be smoke or pets or whathaveyou, our customers have been largely pleased with the results (and when they’re not, we’ve bent over backwards until they are; such is the necessity for a startup in this economy). Of course, it’s just a matter of time if whatever odor-causing agent is still present or re-introduced to said odor-free environment. But with a UV lamp installation, I gather the two agents (ozone vs. VOC’s) are pretty much offset, leaving a clean-smelling environment.
Again, I’m not an expert (but not a complete know-nothing, either). If you want to shoot me an e-mail I can send you a few of the studies (the unbiased ones, AFAIK) that can help you decide for yourself.
Movies, music and magic. I wish I had thought of that.