Being a UV Applications Engineer I typically rely on testing, fact checking and so on. Relying on research information areas such as EPA News or the EPA Publications, which prove the effectiveness of UV Air purification products. But practical experience really does speak for itself. Prior to installing a UV Germicidal bulb in my home’s air conditioner. My step-son had a chronic cough since we had moved in the house a couple years ago. We had never taken note of this until the installation of the UV Germicidal Light. That night it immediately made a difference in his coughing spells he would have while he slept. Thinking maybe this was a coincidence a few months went by and the cough started again. Well while I was putting away decorations for the holiday that had just passed, I noticed that the UV light was not on. Well without telling anybody in the household I decided to just replace the UV Lamp and waited to see if anything changed. Well that night the coughing subsided again. At that point I proved to myself without a doubt the UV Light in the air handler was making a positive impact. Instant irradiation of the mold spores on the coil seemed to have an immediate effect on his breathing. In addition I haven’t had to have my coils cleaned since I installed the UV system 3 years ago.