This topic caught my eye, and I thought I'd comment on it since this is my area of expertise (academically speaking).
When something says that it emits non-detectable amounts of ozone, that does NOT mean that the amounts of ozone are so low that they do not cause any problems. Non-detectable means that the amounts are so small that the equipment used in a lab to determine the concentration of ozone is not sensitive enough to pick it up. It's like putting a paper clip on a bathroom scale. The bathroom scale would read "0lbs" but you know that doesn't mean the paper clip doesn't weigh anything...it just means it weighs too little for the scale to notice.
I used to have a water purifier that used UV radiation, but I stopped using it. The thing that concerns me most about using UV for things like cleaning the air and water is that UV breaks apart the molecules in the air, resulting in ions. (An ion is a negatively charged particle.) These ions can "stick" to other things, and scientists don't really know yet the long term effects of what can happen when ions stick to other positively charged particles.
In all likelihood, the system you have is probably very safe. Most HVAC systems have to adhere to very strict regulations, and if the main goal is to kill mold, viruses and bacteria, you've made a good investment.
Would you maybe PM me with a little more information about your particular HVAC system? Is the UV housing a free standing unit somewhere in the home, or is it concealed up in the attic or crawlspace? Does it run all the time, or can you turn it on/off
As far as ozone emissions are concerned, you're probably not going to have a problem. Ground level ozone can reduce lung capacity, so if you notice yourself having more difficulties than normal, try leaving the unit off for a week and see if you notice a difference.
Good luck! I'm curious to hear more about it.
<a target=_blank class=ftalternatingbarlinklarge href="http://www.associatedcontent.com/article/78634/limiting_exposure_to_mold_in_the_home.html">Limiting Exposure to Mold in the Home</a>