What are factors that influence the choice of a UV system to disinfect pool water?
An appropriate UV system properly installed in the water treatment plant of a swimming pool is undoubtedly a guarantee of improved water quality and increased bather satisfaction. However, it must be emphasized that no number or type of UV system can remedy the problems caused by inadequate pool water treatment plant design.
Before the installation of a UV system is considered, it must be ensured that the basic swimming pool water treatment plant is correctly and appropriately designed and sized.
Much literature exists covering the design of pool water treatment systems. National standards sometimes lay down mandatory treatment methods as well as prescribed water quality limits. However, the following is a brief summary of the provisions that need to be made before a UV system can make any contribution to the pool water quality:
1. Adequate pool turnover
There is no point in installing a UV unit if the rate at which the pool water is treated by it is inadequate. Pool turnover (filtration rate) is set according to national standards, although these are sometimes an absolute minimum. The pool turnover is chosen according to the type of pool. The following are sensible guidelines and are acceptable by most standards:
2. Adequate filtration
There is no point in installing a UV unit if the water filters are not effective. Pool filtration increases the water transmissivity, increasing the effectiveness of the UV treatment. If necessary, flocculation of the pool water should be included in the water treatment plant.
3. Adequate pH control
Although this does not affect the effectiveness of the UV system directly, it does affect the efficiency of the residual disinfectant and the formation of chloramines. The pH of a swimming pool should generally be controlled between the values of 7.2 – 7.4
4. Disinfectant dosing
Provision must be made for the dosing of the residual disinfectant into the pool water, for example chlorine or other disinfectant.
5. Water hardness
Excessive water hardness will cause scaling on the UV lamp sleeve. This will lower the effectiveness of the UV system and increase the frequency at which the quartz sleeve must be cleaned.
6. Pipework and electrical design
The UV system must be designed and piped to accommodate the full flowrate of the pool circulation system during normal operation.
Become an expert on UV systems to disinfect pool water - read the full report about UV systems.