Building Energy Management Systems (BEMS): Making best use of them

The control of energy in buildings is generally poor, despite the availability of a range of tried and tested systems. Building Energy Management Systems (BEMS) are commonplace in larger buildings and are rapidly becoming standard. This has been recognised by the industry, culminating in the publication of BS EN 15232:2012 (Energy performance of buildings — Impact of building automation, controls and building management). This European Standard is aimed at the design of the systems and not at how to maintain and operate them. The impact, in practical terms, is that the design of such systems is generally very good and commissioning is acceptable. However, the understanding and operation of such systems at the user level is generally poor. As a result, the need to maintain these systems to realise the ongoing saving potential is not generally recognised by the end user and/or the engineering services provider, which often means that the systems are not maintained to the level required. In addition, the settings are not reconsidered and revised when significant changes occur to either the building or how it is used.¹