KNX is Green!

Studies reveal that networked home and building control based on KNX allows up to 50% energy savings. The threat of climate change and ever-depleting resources mean that efficient energy use is a key social issue. Because they account for 40% of total energy consumption, buildings represent considerable energy-saving potential. KNX meets the requirements of the top Energy Performance Class for building automation as per EN 15232. This means that KNX is ideally suited to fulfilling the tightened energy consumption requirements for buildings. Through intelligent control of building system technology with KNX, the energy consumption of a building can be halved. Results of current research show how important building system technology is in meeting ambitious climate protection targets.
Intelligent control of building systems reduces energy consumption and the associated operating costs many times over: this is the conclusion reached by the Institute for Building and Energy Systems at Biberach University of Applied Sciences, Germany, following extensive research into the potential energy savings that can be achieved using modern electrical installation systems such as KNX. It sums up its results as follows: “Particularly automation functions which present a high degree of energy-saving potential by combining various individual trades can today only be achieved using modern building system technology based on bus and communication systems.” Conventional electrical installation systems quickly reach their limits in these situations. Another research project, conducted at Bremen University of Applied Sciences, shows the extent to which energy savings can be achieved. The newly-constructed Centre for Informatics and Media Technologies (ZIMT) has been fitted with KNX controls and equipment for regulating heating and lighting. The data collected have been evaluated, and comparisons made between “normal” operation and “automation” mode.

The building has a specific energy consumption of 60-75 kWh/m²a. Two identical classrooms were selected as test rooms. One was fitted with a conventional installation, and the second with KNX control. Based on a four-year series of measurements, the use of KNX control was found to reduce energy consumption by an impressive 50%. It is thus clear that the capital expended in building automation system quickly pays back. Bremen University of Applied Sciences calculated that, with an annual energy consumption of 230,000 kWh for lighting alone, the investment would pay itself back after just one year with a KNX bus control. And ultimately it is not just the owners/operators and investors who benefit from the reduced energy consumption: the climate does as well. In summary, KNX allows the following energy savings to be made:

  • up to 40% with KNX shutter control
  • up to 50% with KNX single room control
  • up to 60% with KNX lighting control
  • up to 60% with KNX ventilation control

From a press release issued by the KNX Association in June 2008

The graph above shows the comparison of energy usage in the study by the Bremen University of Applied Science. It relates to the energy used in the heating systems of two areas, one controlled with KNX and the other conventionally controlled. It can be seen that the KNX controlled installation (red) clearly consumed energy at almost half the average rate of the conventionally controlled installation (blue) over the period of the study.