The costs relating to water consumption and the energy associated with DHWS are significant and the first step in bringing them under control is effective metering i.e. the correct type and quantity of meters with an automatic means of reading and analysing the metering data. This data can then be used to provide management information. on consumption and consumption trends with respect to time of day and usage patterns. Irrespective of the size and diversity of building types and occupation, making information available combined with establishing individual or group ownership and responsibility for consumption is the key to reduced costs. 

The starting point is the water company utility meter. Is it correctly sized and is it accurate? Without sub-metering this is the only source of information regarding the consumption of the site and in most circumstances it also determines the sewage charge for the site. So it’s clearly important that its working correctly and with the addition of automatic ½ hour meter reading it can provide considerable information regarding the consumption patterns and trends for the building.

For example reviewing the ½ hour consumption data can identify peak consumption periods to be investigated and the night time consumption profile can be used to identify water leaks or the operation of automatic functions, which are using water and may be reduced! The accuracy of the main utility meter can be established by using a check meter; this could be a temporary in-line meter or a portable or fixed clamp-on, ultrasonic flow meter such as the Micronics U1000 inset, which can be quickly installed to shadow the meter and provide ½ hour consumption information.

Having addressed the incoming water supply the next task should be to consider the potable and DHWS consumption by Water Accountable Areas (WAA). A WAA is an area of the building or a specific task or process, which represents a significant proportion of the overall consumption for the building. An area could be the water demand related to a specific business function or department, which is in an area where the potable and/or DHWS water pipe-work lends itself to being metered as a WAA or the individual water supplies to kitchens or leisure facilities within the building as examples of building processes. The key point here is that these individual WAAs all make up the whole and if they are monitored with individual or specific group responsibility they can be managed and hopefully waste can be minimised, usage optimised and overall consumption can be reduced.

Benefits – consumption and associated cost reductions – can be derived from temporary and/or fixed sub-metering of water services. Temporary sub-metering of WAAs can be achieved easily using a portable clamp-on ultrasonic flow meter such as the PF330 inset, which with its integral logger can be used to profile consumption patterns and provide information to identify waste and enable corrective action e.g. automatic urinals, which are continuously flushing or not so automatic taps or showers! 

Case study

As an example of temporary monitoring Network Rail used Micronics – Flow Measurement and Analysis services to help them in their Survey of Water Services at Paddington Station. Having been established for many years and subject to considerable development activity over the years the Paddington Station water supply network is understandably vast, complex and to some degree uncharted. So the task of surveying the site to establish what was flowing where was challenging.

Faced with higher than expected water bills the Paddington Building Services Team of Network rail was presented with the daunting task. Having considered various survey options the management team opted for the Flow Measurement and Analysis services offered by Micronics using the company’s expertise with its Portaflo 300 – Time of Flight – portable flow and logging instruments. Six Portaflo 300 – instruments were used in two surveys to gather 24 hour consumption/load profiles for selected Hot and Cold water services including supplies to public conveniences. And the information gathered provided a valuable insight into what was being used – and where – across the station.

Fixed or permanent sub-metering of water services as part of an aM&T or BEM’s system within a building can provide the information needed and check incoming water services on a continuous basis. As such, it should be part of the original design brief for new build or major refurbishment. And if installed with the general works given the relatively small size of potable and DHWS pipe-work in-line mechanical meters will probably be the most cost-effective option. However, the potential for retrofit of sub-metering in existing buildings is extensive and here fixed clamp-on, ultrasonic flow meters such as Micronics’ new U1000 inset, will provide an effective solution and have additional benefits including no pipe cutting and dry servicing. 

Percy Albuquerque, MD of PA Energy which is a specialist flow metering retrofit installation and remote flow monitoring company, says: “We have found that applying the Micronics U3000 and U1000 Ultrasonic flow meters has made implementation of retrofit critical flow measurement straightforward. Often the more innovative energy and environmental managers in our customer base want to understand more about thermal flows in renewables such as solar thermal, or general water flow volumes – for example rain water harvesting – or check metering the water supply company’s own meters for accuracy; using the non-invasive technology makes retrofit flow metering a much more practical proposition by avoiding the need and associated costs of draining down systems that would otherwise result from the use of in-line meters.”

The benefits of temporary and fixed meter sub-metering of potable and DHWS are clear and the tools to do the job are available. Reductions in water consumption and the energy related to potable water and DHWS are achievable with WAA and an effective management system.