Smart controls offer industrial and commercial facilities an effective way to save energy with minimum supervision. Gareth Rowlands, Product Manager for EIB, ABB low voltage products, explains how intelligent building controls can be used to reduce the energy consumption of factory buildings and plants.
The industrial sector is one of the UK’s biggest single consumers of energy. Despite many companies taking steps to improve their energy performance, there is still much that can be done within the sector to ensure that energy is consumed as efficiently as possible.
Apart from Government legislation, one major driver is the spiralling cost of gas and electricity. With recent further increases, energy costs continue to seriously impair the competitiveness of UK industry, providing a major incentive for companies to employ every possible measure to reduce their energy consumption wherever possible.
Much is already being done on the factory floor to achieve this. Energy-saving components such as variable speed drives and the latest high efficiency motors are producing drastic improvements in many industrial processes. The use of more sophisticated controls such as PLCs is also playing a major role in boosting performance.
However, such devices focus on reducing the energy use of processing machinery and not the energy consumed in other areas outside of the production area.
In these areas, the two major sources of energy consumption tend to be lighting and heating, including air conditioning. With these two areas alone accounting for as much as 28% and 64% of a company’s energy overhead, improving the control of lighting and heating represents a major starting point for any company serious about cutting its energy bills.
Furthermore, much energy is also wasted by staff leaving machinery or PC equipment on standby, forgetting to switch room lights off, and not lowering thermostats on warm days. Energy is also lost in the larger spaces factories occupy, often through doors left open in loading areas.
This is where smart building technology can help. Already used in many commercial and industrial applications in continental Europe, smart building controls can help to achieve dramatic changes in the way that energy is managed around a site.
The latest smart control technology can sense changes in the surrounding environment and relay them back to a controller for subsequent action. Using a combination of sensing and actuation equipment, it is now possible for a system to detect changes in elements such as lighting, ambient temperature and even atmospheric pressures. In the context of lighting and heating control, this information can then be used to automatically control opening or closing of blinds or dimming lighting levels or closing windows and turning down thermostats to better control room temperatures. They can also be used to control the opening and closing of doors, either in offices or the large bay doors in warehousing areas.
When linked to PIR (Passive Infra Red) sensors, these controls can become even more sophisticated. The sensors can be used to detect human presence in a room, switch on lights, adjust room temperature and open blinds. Once the person leaves that room, all of its elements can revert to settings to ensure that minimal amounts of energy are deployed. This reduces the need for staff to remember to turn off lights, or lower thermostats.
While smart controls may appear a good idea, the practical implications and costs involved in wiring a fully-functioning factory building have previously proved prohibitive. However, the open-standard control system offered by companies such as ABB is now providing an alternative solution.
ABB’s EIB/KNX system works in a fundamentally different way from conventional smart building systems, in which central controls open and close a separate electrical circuit to activate each individual device, such as a light, blind or heating element. This conventional approach relies on hundreds of power cables to effectively distribute commands around the building.
With ABB’s EIB/KNX system, a sensor or control device such as a light switch sends a control signal over a twin-core data cable or bus to an actuator, which then controls a device locally. This approach yields a true two-wire system, without the need for hundreds of wires providing separate circuits between a central control point and each light or other device.
The additional appeal of EIB/KNX control systems are that they are an open standard platform, making integration with lighting, heating and air conditioning and existing BMS systems easier.
The benefits of this technology can be clearly highlighted by reference to the table. Compiled by the Carbon trust, these figures compare the typical energy use in a modern UK office building (fig 1) with a scenario where a combination of smart technology and good housekeeping measures are employed (fig 2).
So how much could a commercial or industrial user expect to save by employing smart technology? Based on experience gained from its installations worldwide, ABB estimates that users could potentially achieve a 35%-50% reduction on lighting bills. For heating, there is a potential saving of up to 6% up for grabs for every 1°C lowered on the thermostat.
Together, these savings can more than offset the initial outlay of installing a smart control system. In a commercial environment, the outlay will be recouped after approximately 2.5 years. Although the amount saved on energy costs varies by the size and location of the facility, and how much energy is used, savings in industrial facilities can expect to be made much sooner.
Intelligent building controls offer industrial and commercial companies massive scope for managing energy efficiently and taking the responsibility away from staff. This way, key elements such as air conditioning, heating and lighting can be automatically set and managed to suit the factory and reduce overall levels of energy consumption.
