The Carbon Trust believes that BEMs can reduce total energy costs by 10 per cent or more. This is because it offers operators a real-time understanding of building performance and options for energy efficiency improvements. As the BEMS records historical energy data, this can also be used for longer term comparison and benchmarking purposes.
As well as optimising energy consumption and thermal comfort conditions, the BEMS will also allow the building manager to more effectively respond to HVAC-related complaints. As remote monitoring and control is possible there is also potential for facilities management savings, as fewer operatives may be required to run the building.
As BEMs cannot compensate for an inherently inefficient building design, its specification should be well thought out at the design stage, and a clear functional specification created, which considers all the necessary requirements. This will ensure that there is capacity within the system to respond to all functionality, so that energy consumption can be effectively monitored and understood. For example, you don’t want to get to the commissioning stage of a BEMS and realise that there aren’t enough points to connect all of the meters that will be used to monitor energy consumption throughout the building. The user-friendly nature of the system interface is also a very important consideration from the start.
As BEMS continuously maintains the correct balance between operating requirements, external and internal environmental conditions and energy usage, it allows the optimal level of energy efficiency to be achieved. However, to optimise these benefits there should usually be a trained building manager who is the single point of responsibility for the operation and upkeep of the BEMS. This means that there must be some level of investment in regard to employing and training suitable and knowledgeable staff to operate it. At the point of system commissioning, a clear and concise handover to the building manager and team must also be actioned. To give staff the confidence and understanding that is necessary to optimise BEMS use and maximise the benefits of these complex systems, staff may require further or ongoing training and support.
The ability for the BEMS to integrate with other new and existing/legacy hardware and software should also be considered. For example, if closed protocol systems are deployed the end-user will be tied to a single manufacturer and the system’s various components, both new and old, may not be able to communicate freely. This would be especially important on a campus where multiple buildings are being monitored, or where remote access is needed.
In the past BEMS was only used by larger businesses due to cost. However, now it is a more widely accepted and cost-effective option for a broader set of organisations. Likewise, as all buildings need and use controls nowadays, BEMS can be cheaper than individual controls, when you go beyond first costs and consider whole life costs compared to energy savings.
For example, the new Gorbals Health and Care Centre in Glasgow has a BEMS installed. The facilities management (FM) contract requires the FM team to collect the energy and water consumption data, compare that to what was expected and then analyse any discrepancies, with a view to adjusting systems if they are not operating as designed. The inclusion of the BEMS now makes this process a very manageable and efficient task. The metering configuration at the new health and care facility also makes it very easy to extract energy usage data for individual departments via the BEMS interface.
While the implementation of a BEMS may require a certain level of initial investment, in the long-term it will deliver significant payback by ensuring that a building operates at maximum levels of efficiency by removing uneconomical energy usage and associated costs. This also addresses the concerns of end-users as they become increasingly conscious of their role in global energy consumption levels. Consequently, there is a growing demand for greener buildings amongst tenants. Such buildings also provide more effective control of the internal comfort conditions, delivering other positive impacts such as increased employee productivity.
BEMS is the key to this goal as it is much more than just a tool for energy conservation and is being used increasingly as a strategy to reduce both energy consumption and overall operational costs. Building owners and operators who want to improve the quality of the internal environment and reduce energy consumption must move beyond simple energy conservation efforts, towards practices that optimise effective building controls which increase the efficiency of their energy usage and deliver utility savings. The industry is now also focusing on performance in use, by seeking ways to close the gap between regulated/predicted/designed energy consumption and what is actually being consumed.