Delivering the potential of a BEMS
Very many building energy management systems do not function correctly, which is a major opportunity in its own right. Joanne Merry of TEM looks at the benefits of effective energy management.
According to the European Union, buildings consume 35% of Europe’s energy and account for 40% of its greenhouse gas emissions. However, this energy use could be reduced by 20%, resulting in up to a 30% reduction in related carbon-dioxide emissions through energy efficiency measures.
A building energy management system (BEMS) is integral to any building’s energy-efficiency strategy and is often hailed as a saviour for any energy and facilities manager. However when a BEMS is not operated and maintained correctly it can become more of a burden than a blessing and the cause of higher energy costs and inefficiency.
A BEMS offers insight into a building’s performance — including heating, cooling, ventilation and lighting, showing data on a computer screen in real time. If used correctly, a BEMS can reduce total energy costs by 10%. However, they are complex systems, and building engineers are not always fully versed in how these systems should be set up and maintained. There can also be communication issues between BEMS software engineers, maintenance engineers and building occupants.
It is estimated that as many as 90% of all existing buildings have inapplicable or ineffective controls and that many require complete refurbishment of BEMS systems.
Incorrect temperature set-points and time schedules can significantly increase plant running time, energy consumption and maintenance costs. A full BEMS review will easily identify and correct any problems and achieve substantial financial savings.
In an ideal world a building’s BEMS should be reviewed at least every month to check that the settings match how the building’s demised spaces are utilised. This will help to optimise internal conditions and enable on-going energy savings.
The data produced by a BEMS can aid better analysis, understanding and improvement to a site’s energy use through management and exception reporting. When the data is interpreted correctly, a BEMS can provide value for money in terms of payback through reduced energy costs and payments into the CRC EES. However poor maintenance, such as wrongly calibrated and positioned sensors which result in inaccurate data (rubbish in rubbish out), can have the potential for BEMS errors to go undetected for years, increasing costs and causing negative environmental impacts.
For example, after undertaking a survey and thorough investigation into a client’s BEMS, TEM identified that a poorly sited temperature sensor had been causing errors to the day-to-day function of the BEMS. After relocating the sensor, TEM enabled its client to receive energy savings of 54%.
A correctly functioning BEMS can have a positive effect on many aspects of a building, including improving plant reliability, — enabling effective response to HVAC-related complaints, provision of readily available information, computerised maintenance scheduling, effective use of maintenance staff and early detection of problems. It is essential that companies are proactive in engaging their employees with their CSR (corporate social responsibility) and energy-reduction objectives, as well as training maintenance teams to correctly use and manage the BEMS.
Correct heating, cooling and lighting control in working areas produces a consistently comfortable environment for building occupants and can lead to increased tenant satisfaction and greater productivity amongst staff. According to the Health & Safety Executive (HSE), over three million workers in 2009/10 claimed that they suffered from work-related ill health caused by issues such as sore eyes from poor lighting and headaches from an uncomfortable office temperature. Ensuring your building’s BEMS is working at its optimal level can provide an easy solution to ensuring a healthy workforce.
Companies need to foster buy-in from all staff because sustainability programmes built on a high level of employee engagement perform better and provide tangible benefits to the employees and the company. It is estimated that UK businesses could save £500 million by engaging employees in company energy- and waste-reduction strategy; in times when budgets are tight effective energy management has never been more important.
A BEMS, when run effectively, has the potential to be a panacea for all energy-efficient buildings by optimising building performance and aiding energy-cost reduction. However, continuous maintenance and examination is required to maintain optimum energy efficiency levels, and these measures need to be accompanied by engaged employees and a suitably trained maintenance team.
Joanne Merry is technical director with Total Environmental Management (TEM).