BACtwin: opportunity for climate-neutral buildings, Green Deal and circular economy

BACtwin is the digital twin of building automation. The GA function list has established itself as its central building block in accordance with world standard 150 16484 Part 3 "Building Automation Systems (GA) - Functions" 2005). It is available in Excel format and is accepted in the industry. However, the advantages of digitalization and standardization only come into play if economies of scale are exploited and media discontinuities in the process are avoided. In this way, considerable savings can be achieved with much less investment than insulating the building, replacing the windows or similar measures.

One organization that has been successfully using BACtwin for more than five years now is the Austrian Armed Forces (ÖBH) - in particular to implement the goals of climate-neutral building management, the Green Deal and the circular economy of the European Union.

Read more in the guest article by Prof. Rupert Fitzenwallner, who reported on the possibilities offered by the digital twin BACtwin in combination with the use of the Internet of Things (IoT), Long Range Wide Area Networks (LoRaWAN) and a professional energy management system for implementing the energy transition at a BACnet symposium of ICONAG-Leittechnik GmbH in Idar-Oberstein in summer 2022.

Using economies of scale, avoiding media disruptions
One organization that has been successfully using BACtwin for more than five years now is the Austrian Armed Forces (ÖBH) - in particular to implement the goals of climate-neutral building management, the Green Deal and the circular economy of the European Union. For the selected BACnet objects, the ÖBH provided clear specifications regarding the properties (characteristics and information) to be used. The result is a BACnet function list extended to the left by the structured object naming. To the right, the BACnet properties were added to the BACnet function list.

Illustration: Digital twin of the GA with BACnet.

However, the benefits of digitalization and standardization only come into play if economies of scale are exploited and media disruptions in the process are avoided. The fact that the same components are implemented uniformly with BACnet means that users no longer have to plan twice, and engineering and, in particular, operating the systems becomes easier. In simplified terms, one could speak of "series production"; not every pump is implemented differently.

If an organization operates several properties, if a planner creates several plans or if an integrator implements several building automation systems, the interoperable communication protocol "Building Automation and Control Networks" (BACnet) is indispensable. BACnet has existed as a communication standard for 25 years and has achieved a high level of market penetration and maturity worldwide (Revision 21). BACtwin is intended to exploit the advantages of digitalization for planning, engineering and operation, whereby the organizational part of ISO 16484 Part 3 is still available in the first version from almost 20 years ago.

A mammoth task for politics and business
Here are some figures to illustrate the topic: Despite many measures to save energy, energy consumption in Austria has remained constant since 2005. The Austrian government program now stipulates that the 98.5 TWh used annually as heating energy must come from CO2-neutral energy sources by 2040. This represents a mammoth task for politics and business, which can only be implemented economically through digitalization.

By digitizing building automation, considerable savings can be achieved with much less investment than by insulating the building, replacing the windows or similar measures. These immediate savings can then be used for additional insulation. Digitalization also makes user behaviour transparent - and this enables the most efficient and effective measures in the heating transition to be developed. Interoperable digitalization also means that the necessary information is available at the right time. The building of the future must also meet the user's needs. Users will only feel comfortable in the building and act in an energy-efficient manner if the current demand can be controlled in concrete terms using information from the BACtwin.

Implementing an interoperable solution
The Austrian Armed Forces accepted this challenge almost a decade ago and developed an interoperable solution in an open process with the industry. In order to largely eliminate media discontinuities between client specifications, planning output, engineering and operation, the Austrian Armed Forces developed the BACtwin concept, which has been implemented in the properties for more than five years. In addition, a testing tool, an implementation guide and a GA library for the BACtwin were created.

An "upgraded" BACtwin will be published in Germany in the summer of 2023 via an AMEV (Arbeitsgemeinschaft öffentlicher Auftraggeber) set of rules for public buildings. The BACtwin will then be incorporated into the standard performance book for the construction industry. As
some parts of the GA industry do not yet know how they want to deal with BACtwin, it will still take a while before the gap in the GA world standards is closed.

Furthermore, the Austrian Armed Forces have standardized elements of the building automation system such as units (motors, fans) and systems so that they can be implemented digitally throughout the entire building life cycle - from planning to implementation and operation - without media discontinuity. The use of the uniform building automation library injected by the Austrian Armed Forces supports the implementation of the Green Deal and the circular economy in terms of efficiency and effectiveness for the properties of the Austrian Armed Forces.

Conclusion
For the first time, BACtwin has made it possible to automatically check structured building data and exploit economies of scale. Structured data is the prerequisite for reducing the CO2 footprint. Thanks to the GA library for BACtwin without proprietary elements, planning, engineering and operating processes can be standardized to implement CO2 and cost savings without a long lead time.

Due to the issue of CO2 taxation and the planned mandatory refurbishment of existing buildings, it is increasingly important to implement the most effective measures first. In this respect, the digitalization of building automation is indispensable. But what use is the best building automation system if there is no up-to-date input data?

The Internet of Things (loT) and Long Range Wide Area Network (LoRaWAN) offer new opportunities to use the relevant information "just in time" based on user behavior in order to implement the goals of the energy transition. Only through the integrated, standards-based use of the three IT services

• IoT with LoRaWAN (current information)
• BACTwin (control of building information)
• EnMS (energy management system)

it will be possible to implement the goals of the Green Deal and the circular economy without having to forego the achievements of modern housing.

Recommendations from the author
IoT and LoRaWAN are also about being able to read the required information interoperably. Therefore, the first question to ask potential partners is: "What information - in BACnet jargon, properties - do you need?" If a provider wants to read the payload (data
(data of a data packet transported during a communication between two partners that does not contain any control or protocol information) and does not have a suitable parser (computer program that is responsible for breaking down and converting an input into a format that is more suitable for further processing).
format suitable for further processing), end the conversation and look for reputable providers who can guarantee you transparency about your own data.

In the age of digitalization, you need to ensure that you have access to your own data and do not become dependent on sensor providers. Just as you opt for an "interoperable MBE" in BACnet, with LoRaWAN you should opt for an
interoperable LoRaWAN network server.

As a representative of a military organization, on-premises solutions are a "MUST" and cloud solutions are a "no-go".

As the focus is on people and their needs, they do not want to do without the achievements and decarbonization still has to be implemented, there is no way around digitalization in the real estate sector.

Building owners should therefore demand interoperable solutions for automation stations (AS) and management and operating equipment (MBE) and not be persuaded by superficial arguments for proprietary approaches. Proprietary solutions make
dependent on individual manufacturers - and this is always associated with higher costs.

BACtwin article series based on an ICONAG symposium
This article is the second in a series about BACtwin. It is based on a presentation by Prof. Dr. Rupert Fritzenwallner at a BACnet symposium held by ICONAG-Leittechnik GmbH, Idar-Oberstein, in summer 2022, where he reported on the possibilities offered by the digital twin BACtwin in combination with the use of the Internet of Things (IoT), Long Range Wide Area Networks (LoRaWAN) and a professional energy management system for implementing the energy transition.

The third part is about reducing engineering costs through self-configuring management and operating devices based on BACtwin. The author of this article, which will follow at the beginning of May, is Christian Wild, Managing Director of ICONAG-Leittechnik GmbH.

Register here