UV water disinfection provides a broad spectrum solution for bacteria, viruses, cryptosporidium and giardia, while producing minimal disinfection by-products, according to an article published by Water Technology.
Today, many consumers are asking about products certified to NSF standards due to the growing awareness of ultraviolet water disinfection and the increase in government regulated, small, public water systems.
According to the article, NSF 55 includes both Class “A” systems, which require a minimum UV dose of 40mj, for use with waters that are assumed to be contaminated and Class “B” systems, which require a dose of 16mj.
The author discusses the differences that distinguish each classification and why water treatment dealers should be mindful for proper product and application knowledge.
Unfortunately, states the author, many water treatment dealers have had negative experiences with NSF 55 Class “A” UV disinfection systems, mostly as a result of frequent nuisance alarms.
In this article, typical issues and solutions regarding some UV disinfection systems are noted.
Many first time installers make the assumption that, because the product is certified, the end user can expect a positive experience with the equipment.
Typically, product certification standards are written for products that have already been in use for a number of years, resulting in standards which have the benefit of actual field experience incorporated into them.
You can read this entire article on the NSF 55 standard here.