Energy efficiency and the need to reduce the carbon footprint are still high on the agenda. This is down to a number of factors including government targets, the CRC and other legislation, concern over rising fuel prices, fuel security issues and the greater awareness of green issues.
Buildings are responsible for over 40% of the world energy consumption today. It is therefore vital that energy consumption is managed correctly. Often the focus is on how energy is supplied to a building with much debate on the benefits of renewable technologies. These potentially offer carbon footprint reductions but they are not the complete answer. The green energy still needs to be managed effectively within the day to day operation of the building.
This is why a building energy management system (BEMS) is an essential part of any energy efficiency strategy for a building. It can provide a comfortable working environment for building occupants enhancing productivity and contribute significantly to saving energy costs and a reduced carbon footprint if used correctly. All too often the capabilities of the BEMS are not fully utilised and the potential benefits are lost.
The BEMS of today controls many elements of a building intelligently. These systems can all interact and the BEMS can be used as the device to enable this. The Desigo BEMS from Siemens uses open communication protocols including BACNet, LON and KNX which makes this linking
of different systems easier. Many manufacturers now develop their products using open communication protocols. This interaction can enable cost efficiencies and energy savings.
Demand control is key to this but this can often be overlooked. A good example is the use of a CO2 or air quality sensor in a meeting room. This can be used to determine if the room is occupied or not. If the room is empty the lighting can be turned off and the heating temperature setpoints reduced as an energy saving measure. As the room starts to become occupied the sensor and the BEMS controller can then decide how much ventilation is required and only run the fan at the required level, providing variable speed drives are fitted.
An advantage of a BEMS is that it can be retrofitted to an existing building. Installation in most cases is relatively straightforward and users can benefit from a fast payback period. Existing systems can be upgraded to allow additional control functions or new technologies to be utilised.
It is important to implement a regular maintenance programme for the BEMS. A regularly maintained system will work far more efficiently than one that is not maintained. The systems are installed with the best of intentions but can often be neglected after installation. Any number of things can change. Perhaps the most common is that settings are altered to deal with a particular set of conditions and are never restored to their original values. A systematic, regular, well planned maintenance programme can ensure these areas are checked and that the system is run at its most efficient level.
Another vital element the BEMS provides is information. Data from meters can be integrated into the BEMS and this can be used to provide information to the user on consumption. However just collecting metered data is not enough; this must be interpreted and acted upon to ensure that the building runs as efficiently as possible.
This information can also have another benefit for the building users or owners as it can be used to encourage the staff within the building to understand the amount of energy being consumed and encourage them to take an active role in trying to reduce it. The Green Building Monitor from Siemens takes advantage of this public appetite for greater information. This software application allows the user to display current and credible statistics about their building’s actual energy usage, CO2 reductions and water conservation making their energy profile transparent.
Far too often many of these features are neglected and the BEMS is installed and then forgotten about. The BEMS can be the most vital element to any energy saving strategy in a building, so make sure your building is getting the maximum benefit.