UV can also improve air quality
The key to maintaining a safe aquatic environment is proper water chemistry. Unfortunately, as chlorine reacts with ammonia and organic compounds introduced to the water via bathers, harmful and foul-smelling disinfection byproducts (DBSs) (i.e. chloramines) are produced.
Studies show UV-C light not only disinfects pool and hot tub water but it also removes chloramines—the leading cause of poor air quality at the surface of the pool and surrounding area, especially in indoor facilities. UV-C light destroys chloramine formation at the molecular level before they evaporate.
Using UV technology, as opposed to other methods of chloramine removal (e.g. hyper-chlorination, non-chlorine shock, ozone and adding fresh water) can help eliminate water maintenance inaccuracies such as combined chlorine reduction calculations, while also reduce operational costs by eliminating the need to close the facility for non-chlorine shock treatments and adding treated and heated fresh water.
European centres for water standards, such as Deutscher Verein des Gas- und Wasserfaches (DVGW), the German technical and scientific association for gas and water, and Österreichisches Normungsinstitut (ON), the Austrian standards institute, have certified UV light reactors to be effective not only in pool water sanitation but also in improving indoor air quality.
Choosing the right system
It is important to seek references when considering a UV sanitation system, as an inadequate system may not perform the job properly or comply with sanitation regulations.
For instance, checking the system’s certifications (e.g. energy efficiency ratings, maximum flow rates, etc.) with the manufacturer is a good idea, while referring to NSF International’s website (www.nsf.org) for its list of approved UV water treatment systems is another. Some provinces and states also maintain a shortlist of authorized systems.
In addition to researching the product, other variables to consider include system size, low versus medium pressure lamps, wattage, spare parts/maintenance and cost/payback.
The Right UV-C Dose |
|
|---|---|
| Bacteria | UV-C Dose (mJ/cm2) |
| Bacillus Anthracis | 8.5 |
| E.Colis | 7 |
| Légionnella | 3.8 |
| Pneumophila | 10 |
| Salmonella enteridis | 7.8 |
| Streptococcus Faecalis | 10 |
| Vibrio Choléra | 6.5 |
| Algae | UV-C Dose (mJ/cm2) |
| Chlorella vulgaris | 22 |
| Protozoa | UV-C Dose (mJ/cm2) |
| Cryptosporidium | 22 |
| Virus | UV-C Dose (mJ/cm2) |
| Hepatitus virus | 8 |
| This chart gives the levels of UV-C doses (needed to destroy 99.9 per cent of micro-organisms.) | |
System size
The size of the UV system is determined by the type of pool (i.e. commercial or residential) as well as its use. Water flow and bather loads should also be factored into the equation. For example, the needs of an indoor Olympic-sized pool with heavy bather loads will differ substantially from an outdoor, mid-sized pool at a hotel.
The UV technology needs to fit the environment and should be affordable so the facility can reap the benefits.
