Building automation steps out of the sideline
Building automation has the proven potential to make a serious dent on a building’s energy cost — and much more effectively than other approaches to the task. Graham Martin of EnOcean Alliance discusses how the concept is receiving greater recognition.
For years, energy policy has mainly focused on different sources of renewable energy. Politicians, economists and other commentators still discuss the best-performing technologies and the requirements of the power grid. However, recently another perspective is attracting more attention — energy efficiency as a valuable ‘source’ of renewable energy.
The UK’s National Energy Efficiency Action Plan sees it at the heart of the Government’s long-term energy and climate change plan for low-carbon growth. This includes ambitious goals of reducing primary energy consumption by 20% of the 2007 level by 2020.
Achieving this saving requires rapid action now.
Existing buildings provide great potential to improve their performance. They consume up to 40% of primary energy and are therefore more power-hungry than the industrial sector. However, energy-related renovations such as new insulation or a more efficient heating system are costly for businesses and home owners alike. Despite the potential savings available, the necessary investments cannot generally be made in the short term, which could hold back the potential efficiency benefits for years.
Does energy efficiency remain a luxury? Not necessarily. There is a measure that is beginning to come to the fore in discussions — building automation. With publication of the Building Renovation Strategy as part of the UK’s National Energy Efficiency Plan, building automation looks set to play a key role in delivering energy efficiency.
Building automation can control systems such as heating, ventilation, lighting or shading in accordance with individual requirements. The goal is to consume only as much energy as is actually needed.
Such systems are already intelligently connected within a building and often learn the occupant’s behaviour automatically. Room sensors deliver data as a basis to analyse a building’s heating and cooling rate as well as its physical fabrics. Besides temperature, sensors can also detect open windows or whether the relative humidity of the air is too high. Thus, the system automatically reduces the heating or activates ventilation, respectively. In addition, data on light intensity influence the control of lighting and shading.
Current weather conditions, the presence of people in a room, solar radiation etc. are crucial elements of a control that adapts to changing situations and conditions. Usually, there is an immediate saving effect. The more efficiently the various building services are matched the better the savings, which can be up to 30%.
Building automation has a great advantage compared to other energy-related measures. Thanks to wireless technologies, such systems can be easily retrofitted in existing buildings, requiring less cabling and at manageable costs. Wireless sensors to deliver the needed data and execute control commands can be flexibly placed. This capability, for example, meets the requirements of flexible office concepts where partition walls and the floor plan have to adapt to the heterogeneous needs of different tenants. Wireless switches and sensors can be simply moved as required whenever the office layout changes.
Today, wireless devices also operate without batteries. They gain their energy from the surrounding environment, such as the press of a button or indoor light. Even differences in temperature between the heating and the room air can power automatic valve actuators. Using batteryless wireless technology, a system’s operating and maintenance costs are low as there is no need for batteries or staff to change them.
In the housing sector with millions of rented apartments, wireless building automation is also an attractive efficiency measure. Owners or housing associations can implement it without affecting the tenants’ quality of life by extensive renovation, noise and dirt for years. In addition, the landlord does not have to bother the tenant with an annual battery replacement.
Besides flexibility, wireless building automation systems offer significant installation-cost savings. In a new building, they reduce installation costs by 15 to 30% of installation costs; in retrofit projects, the saving can be up to 70%.
Combined with reduced energy consumption, such systems can achieve a payback of one to five years. In comparison, the return on investment (ROI) of new thermal insulation is 10 to 60 years. Consequently, building automation will clearly become the inevitable foundation for energy-efficient buildings.
Graham Martin is chairman of EnOcean Alliance.