All together now
Devising and implementing an energy management strategy across a number of disparate buildings can seem an overwhelming and intimidating task. John O’Leary, Key Account Manager at Trend Control Systems demystifies the process and explains how to maximise the potential of a Building Energy Management Systems (BEMS).
The vast majority of organisations are looking to optimise their energy use however, developing a cohesive strategy that will achieve this objective is sometimes easier said than done. The amount of variables to consider with regards to a single building can appear daunting enough, so it is no surprise that configuring and implementing a system across a number of disparate structures can strike fear into the hearts of even the most hardened building services engineers. The good news is that by tackling the issue systematically and identifying the ‘low hanging fruit’, making immediate savings needn’t be difficult.
Case in point
Healthcare estates and educational establishments are prime examples of environments where monitoring and managing energy use across a number of buildings of different shapes, sizes and ages has to be addressed. Very often they have changed from their original use and have their own unique infrastructures which need to be accounted for.
Regardless of how an estate is configured, the most important thing to do first is to recognise the importance of energy management, understand the benefits it brings and take the time to identify what needs to be achieved. While this might sound simplistic, getting buy in from all areas of an organisation will undoubtedly make the entire process much smoother.
The chances are that each building on an estate will have some kind of BEMS already installed and therefore one of the best ways to review the way they are being used and identify ways to make improvements is through an energy audit.
The word audit is somewhat ambiguous and one auditor’s approach can be very different to another’s. To get the most out of this exercise it is important to commission an expert to carry it out, as only someone with the requisite skills and insight will be able to fully understand the way a building is being used and highlight where its current infrastructure can be enhanced. They will then make meaningful suggestions and present them in a way that enables investment decisions to be made quickly and easily.
A well structured, thorough and professionally conducted audit will ask probing questions, drill down to the finer details and provide guidance about implementing technologies such as air balancers and variable speed drives. Only auditors that have in-depth knowledge about the latest product innovations, legislation and best practice can get under the skin of a building. For example, it’s all very well pointing out that there are two boilers but the real value comes in suggesting how they could be controlled more efficiently.
It is often the case that adjustments can be made to the BEMS during the audit visit itself that will deliver immediate savings, while items such as boilers, chillers, air conditioning and pumps can be checked to make sure they are working correctly. Any maintenance issues to do with the BEMS or the building services equipment can also be dealt with at the same time.
Plan of action
Where having an audit really comes into its own is in its ability to help construct an energy management plan that features a prioritised summary of activities that should be carried out in the short, medium and long terms.
It will help break the project down into bite sized chucks that could initially focus on gathering utilities based data, identifying wastage, and then prioritising ways to reduce energy consumption across the entire estate. Alternatively, it might be better to carry out work on a building-by-building basis, whereby budget can be allocated to each one to make improvements.
An energy audit can lead to some outstanding results, such as those experienced by Sidmouth Hospital in Devon. During a Trend engineer’s time on-site, improvements to its BEMS settings were made which included altering heating times in intermittently occupied areas from 24 hours a day to only between 06:00 and 22:00, and reducing heating setpoints to 21°C. These actions resulted in an estimated £7,000 of savings per annum and a reduction of over 43 tonnes of CO2.
Sweat the assets
When a BEMS is first commissioned it is configured around an existing building layout and occupancy patterns. These can change over time and old and poorly performing time clocks and setpoints; conflicting heating and cooling; incorrectly calibrated control loops, valves, actuators and sensors; new layouts and repartitioning; and the addition or relocation of equipment can have a detrimental effect on energy consumption.
With budgets being squeezed ever tighter, simply ripping out and replacing existing systems is not an option, and there is often pressure from the finance director to achieve more with less money. Therefore, making small adjustments and working with a manufacturer that provides backwards compatible and fully interoperable products can maximise the potential of an existing BEMS. This level of flexibility will enable work to be carried out at the pace that suits time and budget constraints.
This approach can get energy use under control surprisingly quickly and, what’s more, any savings that are made can be reinvested for further activities across the rest of the estate.
Don’t mix and match
As stated earlier, most buildings will have their own BEMS installed. Although being able to control and monitor energy use from one central location makes life much easier for the building services manager, integrating different systems is something that should be approached with caution.
While interfacing one manufacturer’s system into another is possible through the very careful adoption of technology and expert advice, it is complex and the objectives must be very clearly defined at the outset. This is because a manufacturer’s products will be specifically designed to work with a certain protocol and using devices from the same supplier ensures quick, easy and seamless integration of terminal units, controllers and modules. It therefore makes sense to work with products that have been designed and built to operate in perfect harmony with other devices around a specific protocol.
Some engineers also make the mistake of installing a number of different controls providers’ products because certain elements are cheaper. However, a failure to look at the long term picture when using multiple providers can actually result in additional maintenance and repair costs, and drastically compromise the longevity of the BEMS. For example, should something go wrong with a third-party device and a chosen installation and maintenance partner is not able to remedy the problem, it could mean that specialist – and for that read expensive – assistance will be required. Ultimately, it could transpire that there is no possible solution and an entire system, or a big part of it, could need to be ripped out and replaced.
One way that energy related data could be centrally monitored is by feeding it back to a central location using an existing IT network infrastructure. As all buildings on an estate will usually be able to talk to each other via a campus area network it should, in most cases, be possible for the BEMS to operate over this medium and a BEMS vendor will be able to advise accordingly.
The key to immediate savings is to get the ball roll
ing by recognising the need for an energy management plan and configuring targets that are achievable. BEMS are at the forefront of the drive towards greater energy efficiency and the cost savings and environmental benefits that can be experienced as a result of investing in and optimising this technology are considerable and within easier reach than perhaps initially thought.