Modern Building Services

26 MODERN BUILDING SERVICES MARCH 2021 FEATURE WORKING BUILDINGS In this first instance, water systems need to be reviewed to ensure compliance with Legionella Control document, ACoP L8. The flushing through of water through pipes and taps, is part of the design and helps towards healthy and efficient operation, preventing stagnation – many of these empty buildings are designed for thousands of people. If a building is going to remain empty for long periods, reducing the locations where water can sit (and get warm) are key steps in preventing places for bacteria to thrive. This can be achieved by reducing tanks and/or tank capacity. Water heaters can be turned off if hot water is not required - as long as the water is stored at less than 20˚C. And cooling towers, well-documented bacterial breeding grounds, must be tested as normal (weekly and in some instances daily). Where access is not possible, the cooling tower and associated systems can be shut down. Regular sampling is essential, particular after periods of intervention. Drinking water in particular needs to be tested – after a long period of stagnation it may no longer be potable, which could also lead to delays in buildings re-opening. To keep bacterial levels under controls, we recommend using chloride dioxide based chemicals when flushing. Treated water provides a constant low level defence that is far more effective than just using water alone. HVAC health Keeping bacterial levels in-check is not just a public health issue, it’s a HVAC health issue too. The build-up of bacteria, sludge and rust will lead to inefficiencies and potential breakdown. With many businesses taking a financial hit, paying for repairs on an expensive commercial water system is something to be avoided. Cutting corners with ongoing upkeep in this instance is a false economy. For closed systems, we use 24/7 remote monitoring to check condition. This approach provides real-time information and prevents unnecessary site visits – something that’s all the more importance is we avoid travel and social contact to halt the spread of Covid. Industry best-practice Industry guide, SFG30, has been produced to help FMs and maintenance teams take the right steps when bringing a building safely back into operation – covering water and all the other critical building services. This is an unprecedented time in human and building history, so it’s important those responsible for restarting the wheels of office life do so cautiously and safely, utilising expert support and guidance. Guardian Water Treatment has created a free guide to preventing legionella in underused buildings – ‘Locked down but not forgotten’. The company provides essential legionella water treatment services, training and water system management, including 24/7 remote monitoring. Lockdown legionella prevention top tips: • Increase flushing for little used outlets. • Increase microbiological sampling, to check any changes in activity have been effective. • Tank flushing - any site with a tank should increase flushing of tank fed outlets. Where possible, tank capacity should be reduced. • Water heaters can be turned off if hot water is not required - as long as the water is stored at less than 20˚C. Outlets should be flushed daily or as frequently as possible. • Cooling towers - daily and weekly testing and associated tasks must be maintained. Dipslides, TVC and Legionella sampling should continue at the usual frequencies. Total shutdown should be avoided where possible. • Water Softener - salt level in the brine tank should be checked regularly and topped up if required. It is likely that the amount of softened water required will be less than usual. Mothballing and re-commissioning best practice SFG30 provides best practice guide tomothballing and recommissioning. Here are just some of the building services actions need to be considered: • Water: Water systems – for sanitation and HVAC systems - must be cleaned, refilled and disinfected where necessary, with legionella and general bacteria testing used to ensure safety. Drinking water in particular must be tested to ensure it is safe. • Ventilation: If left unchecked, extract ventilation can become hazardous. Build-up of dust and other deposits (grease in kitchens, for example) caused by a lack of use and cleaning could pose a fire risk. Ventilation is also key in the fight against Covid, so ensuring this works well is essential – stale air is a breeding ground for disease. • Critical services: Security and safety can often become more important when a building is empty, as it becomes an attractive proposition for thieves. Fire alarms, emergency lighting and any security systems, must be kept fully operational. • Building Management Systems: Making sure all BMS are working as they should, will help ensure a smooth return to the workplace, maintaining operational efficiency. Workplaces need to hit the ground running once they can. More information can be at www.gwtltd.com