The second edition of the guidance, which was published on 1November 2021, provides best practice advice for facilities managers and maintenance teams responsible for looking after closed heating and cooling systems after a building has been handed over. It has been significantly expanded to incorporate rapid technological developments since the previous edition was published in 2013.

'The updated BSRIA BG50 places a strong emphasis on eliminating the root cause of corrosion conditions, most notably DO, which is not detected by laboratory sampling,' said Toby Hunt, Head of Guardian. 'Corrosion monitoring technology has moved on at a rapid pace in recent years, allowing the presence of DO, together with other critical parameters, such as pH, conductivity, temperature, inhibitor levels and pressure to be accurately detected.'

Real-time corrosion monitoring technology is referenced throughout the guidance as best practice for detecting the onset of corrosion in closed systems, something that is of increasing importance as society's reliance on critical infrastructure, such as data centres, continues to grow.

'Real-time corrosion monitoring technology has been a huge part of our closed water systems treatment since 2017, saving our clients hundreds of thousands of pounds by preventing issues before corrosion has taken hold,' continues Mr Hunt.

'The system we use, Hevasure, immediately notifies responsible parties of changes in system condition, including all-important dissolved oxygen levels, providing the opportunity for preventative maintenance and active service interventions before problems escalate. To date, we have deployed over 70 active systems, monitoring critical HVAC throughout the UK.'

BG50/2021 states that: 'The level of dissolved oxygen is the most important factor related to corrosion,' and that laboratory sampling is not suitable for testing for DO. Compared with sampling, real-time corrosion monitoring is far more accurate and instantaneous, providing a comprehensive indication of system conditions and water quality and critically, it is the only way to detect the presence of DO.

The updated guidance also contains in depth technical guidance on a range of water treatment techniques, explaining how common conditions, such as corrosion, scale, sedimentation and biofouling can be prevented through proper design, construction, maintenance and monitoring.

Mr Hunt concludes: 'This shift in industry best practice after handover - from manual sampling and laboratory testing to real-time data driven solutions, which complement and, in some cases, reduce or replace the need for sampling - reflects similar updates to BSRIA's BG29 guide to Pre-comission Cleaning of Pipework Systems last year. It will result in healthier buildings that perform better, use less energy and cost less to maintain.'