FEATURE ENERGY EFFICIENCY


IS YOUR BUILDING’S ENERGY use out of control?


In this day and age of corporate responsibility and increasing legislative pressure, it is vital that non-domestic buildings control their energy use. This is where building management systems (BMS) come in as Trend Controls explain


T


he cutting of energy usage and carbon emissions is becoming


increasingly more vital and important for owners and tenants of non- domestic buildings. Higher utility prices,


public and stakeholder


pressure to show corporate social responsibility, plus stricter legislation (in 2008 the UK government committed to lowering national carbon emissions by 80% by 2050), means that taking control of a building’s energy usage is a concern for energy and facilities managers globally. Of the energy consumed by


buildings, around 39% of that is wasted. However, in most cases this wastage can be reduced purely through optimisation of the control systems that are already installed.


FIRST PRIORITIES Facilities managers are responsible for ensuring the correct steps are taken towards minimising wastage and preventing energy use from becoming uncontrollable. Knowing where and why waste occurs is the first step to keeping usage under control - resulting in enhanced efficiency and reduced cost. The priority should be to focus on areas


where large energy savings can be made quickly and easily. To achieve this the way in which a building is used must be looked into as well as the settings of the energy management system or BEMS already in place. A BEMS monitors the control of a building’s heating, ventilation, air conditioning, lighting and hot water, while maintaining the balance between energy usage and the building’s energy requirements. A BEMS functions automatically, day


24 NOVEMBER 2014 | ELECTRICAL ENGINEERING


in, day out, and can carry on doing so year after year. However, changes in a building’s circumstance or use, or neglect of the system’s support needs can cause performance to suffer. This leads to an out of control system with higher building operating costs and reduced occupant comfort. In some cases, a fully


featured BEMS may not have been installed in the first place, so that a building’s energy


use will be inefficient from the start. In most cases, developers understand the importance of introducing a BEMS, and will work with design teams to create specifications for a fully featured system in both new builds and refurbishments. However, this is not fool-proof -


the pressures of completing projects on time and within budget can lead to adjustments in the original specification, which may then compromise the effectiveness of the BEMS.


LIVING WITH A BMS When a BEMS is installed, often it will be set to control a non-occupied space. However, once inhabitants enter a building, their behaviour will immediately begin to affect energy performance. Over time, occupants will continue to change the use of the building. Around half of all reductions in energy efficiency are caused by human action and changes in building purpose. Screens, computers, people and office equipment all influence the


environment. Typical examples include: l


Hot machinery which may influence heating sensors and trigger the air


People feeling cold and using plug in heaters would also falsely set off the


conditioning. l


Above: on average, buildings waste approximately 39% of the energy they consume. However, in most cases this wastage can be reduced purely through optimisation of the control systems already installed


BACK IN CONTROL All such things as poor internal positioning, planning, timing and even maintenance issues are fixable at slight costs. Simple system adjustments can be made to regain control. In order to ensure the absolute optimum usage of a BEMS system, a full building energy audit should be carried out, which will allow for carbon emission reduction, boost cost efficiency and ensure buildings maintain the best environment possible for their purpose - inhabitants and usage.


Trend Controls www.trendcontrols.com T: 01403 211 888


Left: in order to ensure the absolute optimum usage of a BEMS system, a full building energy audit should be carried out, which will allow for carbon


emission reduction and boost cost efficiency picture courtesy of Pixomar / FreeDigitalPhotos.net


cooling system. l


Alternatively, opening a window


might trigger the heating. l


Using a room as a canteen without


considering temperature sensor positioning (placing ovens beneath for example) would


add false pressures on the BEMS. l


Even adding partition walls can alter


temperatures, airflows and give false environmental signals. Changes in tenancy, the inhabitant


number and building purpose often won’t consult or match the timers or BEMS controls that are pre-set, causing inefficiency - the heating may run throughout the night when the building is empty for example. Broken valves, pipework, mechanical


failures and inefficient components, alongside poor maintenance, will also contribute to inefficiency and a lack of control over the BEMS system. This in turn will increase energy costs and carbon emissions.


Enter 213 / ELECTRICALENGINEERING


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