Molekule (PECO) vs. UV light air purifiers: How it's different. The Molekule PECO technology has been designed to power its catalytic reaction with UV-A specifically because UV-A is a safe, yet efficient, type of light that does not produce ozone. Unlike Molekule, which uses UV-A light, other air purifiers use UV-C light specifically, either. UV Light Advantages Improve the air in your entire house Deactivate most viruses, bacteria, and mold Increase the lifespan of the system Minimize the potential option of creating an ozone Overall the UV light has the better advantages between the two. The UV light has germicidal light that is very useful in your home..