Residential
Residential UV applications cover a wide range of flow rates and system sizes. In many regions, UV water treatment equipment must be independently tested and certified to a recognized standard. The most common are NSF/ANSI 55, WQA Gold Seal, and CSA B483.1.
Commercial / Industrial
Commercial and industrial UV systems don't always fall under drinking-water regulations, but they still need to comply with specific testing standards. Typical applications include campgrounds, hotels, restaurants, processing plants, and recreational facilities. Common testing protocols include NSF/ANSI 55, ETV, and DVGW.
Municipal
Municipal systems always fall under drinking-water regulations because they supply water consumed by the public. These applications range from small private community systems to large municipal treatment plants. Testing protocols include the USEPA UVDGM (UV Disinfection Guidance Manual, 2006), DVGW, ÖNorm, and NSF/ANSI 55.
NSF/ANSI 55 — Ultraviolet Microbiological Water Treatment Systems
NSF/ANSI 55 is a UV water treatment standard that proves equipment performance under specific conditions, and also specifies requirements for material composition and sizing. There are two classes:
- Class A — for non-potable water that is being disinfected to a potable level. Requires a UV sensor to indicate when intensity drops below an acceptable level. Class A systems must deliver at least 40 mJ/cm² at the alarm set point.
- Class B — for supplemental treatment of water that is already considered potable. Class B systems must deliver at least 16 mJ/cm² at the alarm set point.