What happens to the output of a UV lamp during water temperature fluctuations and how can these impacts be controlled? Read this months newsletter to find out! We also have a special EOFY offer available to all our customers.


The impact of temperature on UV lamp output

Fluctuations in water temperature influences a UV lamp’s UV output and a UV disinfection system’s ability to achieve the required UV dose for sufficient microbial inactivation.

Each UV lamp type is affected differently with the UV radiation of standard low pressure (LP) and low pressure high output (LPHO) UV lamps being the most sensitive to temperature changes. Studies of LP and LPHO UV lamps have shown that where water temperature is 40 Degrees Celsius, a UV output drop of 30% can occur. This drop increases as the water temperature increases. This is especially relevant in warm water recirculation applications or in applications where a UV disinfection system is left on with no flow. UV disinfection water engineers must take this drop into consideration when specifying UV disinfection systems.

The UV output of amalgam UV lamps shows little influence with water temperature fluctuations. This is why amalgam UV lamps are UV-Guard’s first choice when providing solutions for medium to large warm water recirculation systems.

It must also be noted that damage to UV lamps and other components can occur if there is no control in place to prevent a UV system from overheating.

Read more about the different types of UV-C lamps in our Knowledge Centre. The Knowledge Centre page is continuously being updated with information about UV water treatment.


UV-Guard’s thermal relief systems

UV-Guard highly recommends the use of thermal relief systems in any UV installation where there is the potential for the UV system to be on in no flow conditions.

Our larger X-Series systems are supplied with PLC controlled thermal relief valves as standard. We also have fully automated stainless steel thermal relief valves for use with our S-Series, SLT-Series and SLF-Series of systems.

These valves are installed on the outlet of any UV disinfection system, even non UV-Guard units. They are designed to release a small amount of water back to a storage tank or to drain when water temperatures reach 55 Degrees Celsius. The water released is replaced by fresh water which cools the UV lamp and UV system, protecting the UV lamp from damage and ensuring that UV output is not detrimentally impacted by high water temperatures. These valves will operate where pressure activated pumps are used prior to the UV system.


Thermal relief system EOFY special offer

As you know, we don't usually inform you about our promotions in the newsletter, but we are excited to celebrate EOFY by offering our customers a special thermal relief valve deal. Contact us today to find out about our sale offers on the 1”, 1.5” and 2” thermal relief valves. They can easily be retrofitted into existing installations so if you want to improve and optimise your system, or provide this option to your customers, get in touch!


Contact us

Call us for UV lamps and other spares for any brand and model. We hold over 500 lamp varieties in our Sydney warehouse with next day delivery to metro areas.

Working on a new project where UV disinfection is required? Send us the details and we’ll provide the technical support you need along with a proposal to meet your project’s needs.