Hong Kong’s Victoria Park Swimming Pool Complex Using UV to Treat Indoor Pools and Rainwater

The Victoria Park Swimming Pool Complex (VPSPC) in Hong Kong has recently installed 21 Hanovia (UK) UV disinfection systems to treat the water in three of its indoor pools and to disinfect harvested rainwater. The UV systems were installed by Jardine Engineering Corp, with the help of SmarTech HVAC & Engineering, Hanovia’s local distributor.

The main 50 metre competition pool, a 30 metre multi-purpose pool and an indoor Jacuzzi are now all treated with UV. In addition, recycled rainwater used for cleaning floors and toilet flushing is treated with UV prior to use.

“This is a very significant project for us and one that shows just what our UV technology is capable of,” commented Ms Ying Xu, Hanovia’s Asia-Pacific Manager. “VPSPC chose Hanovia because, in their opinion, it’s the ideal technology for swimming pool water treatment. UV not only destroys microorganisms but also removes chloramines, resulting in crystal clear water with no accompanying ‘chlorine’ smell.

“Our UV systems can also be sized to handle a huge variety of flow rates, from as high as 1700m³/hour in the main competition pool to the small flow rates required for rainwater treatment – this was an essential requirement. I think the final clincher was our fantastic reputation in the swimming pool industry and the hard work of SmarTech.”

Chloramines (also known as combined chlorine) are the unpleasant by-products associated with chlorinated pools; they lie as a vapour over the pool surface and cause eye and skin irritations and have a strong odour which is unpleasant for both bathers and staff. Chloramines not only put people off visiting indoor pools – they can also be a health risk if inhaled regularly. A recent paper in the European Respiratory Journal linked high levels of asthma in children with swimming in outdoor chlorinated pools.

Chloramines are also highly corrosive and are known to cause significant damage to the physical structures of some indoor pools, which can raise safety concerns. Medium pressure UV eliminates the problem of chloramines almost entirely due to its wide wavelength spectrum, which destroys mono-, di- and tri-chloramines. A reduction in chloramines also means less wear and tear on the building and less maintenance and repair bills – as well as a safer building.

UV is ideal as not only does it act as a powerful disinfectant in its own right – minimising the use of chlorine – it also destroys any chloramines produced as a result of the residual chlorination, ensuring a healthier environment for swimmers and staff alike. Less chloramines also means lower water bills as less water is needed to dilute and flush the pool. UV is also a clean technology, with no by-products of its own.

Another major benefit of Hanovia’s UV systems is power switching, which optimises power use only when it’s actually needed. This can have a significant impact on a pool operator’s energy bill.

According to the VPSPC management, the UV systems are easy to use and are low-maintenance. “The control system is simple and stable, meaning we don’t need to actively monitor the performance of the UV systems,” said a spokesperson. “We chose Hanovia on the recommendation of other users and have been very pleased with the technology. We do an annual clean of each UV chamber, but this hardly seems necessary as each one remains almost like new. It is also extremely compact.” Compared to ozone treatment, UV is up to five times cheaper to maintain and requires only 1/10 of the space.

The use of UV for rainwater treatment is an interesting and growing application for the technology, particularly in areas of relatively high rainfall such as Hong Kong. Capturing this rain for reuse not only makes environmental sense – freeing up municipal water supplies for domestic and industrial users – it also makes financial sense for the local municipality.

Of the 21 Hanovia UV systems in use at VPSPC, 19 are medium pressure SwimLine systems: eight for the main swimming pool (seven duty, one standby), 11 for the diving pool (10 duty, one standby) and one for the Jacuzzi. One low pressure AF3 UV system is used for rainwater treatment. All the UV systems are located after sand filters in the pool and rainwater treatment processes.