BACtwin

What are the prerequisites for using BACnet in larger real estate portfolios in a vendor-neutral way so that they can be managed in an energy- and cost-efficient way - that was the goal of the symposium "Future-proof technical building management with BACnet - The digital twin of building automation (BACtwin)" on June 21, 2022. For a holistic penetration of the topic, some prominent figures of the GA scene as well as some operators of large real estate portfolios and GA planners had traveled to the Gutenberg Digital Hub in Mainz. ICONAG-Leittechnik GmbH had invited the participants, supported by the other sponsors GEZE GmbH and Somfy.

Necessity of further BACnet specifications

For a future-proof and digitalizable technical building management, it is not sufficient to prescribe only the BACnet standard according to AMEV or other regulations. Probably everyone who wants to manage several buildings with GA systems from different manufacturers from a central location has experienced this by now.

BACman Hans Kranz impressively explains why this is so in his keynote speech at the conference: when the GA world standard ISO 16484 was formulated between 1995-2005, the so-called bus war prevailed. One had to find the lowest common denominator between Profibus, FND, LON, EIB/KNX and BACnet. And this did not include the future-oriented BACnet objects and properties. This created a standardization gap. Since the building owners and their planners according to valid standard to the use of the BACnet objects and their properties no defaults make, the market uses this skillfully, in order to specify under the cover of BACnet the building owner with extensions on the first supplier. This means that the idea of the building owner being independent of the make and manufacturer has been rendered obsolete for the time being.

This standardization gap is still the cause of media discontinuities between the client's specifications, planning output, engineering and operation of GA systems, explained Prof. Dr. Rupert Fritzenwallner from the Austrian Armed Forces (ÖBH). Together with Hans Kranz, he is the author of the highly acclaimed technical book "Der digitale Zwilling der Gebäudeautomation mit BACnet" (The digital twin of building automation with BACnet). In this book, the two experts describe, among other things, how the tool of the GA function list, which has proven itself in GA planning, is to be extended by the building owner's specifications and the installer's specifications in order to arrive at the BACtwin (see, among other things, the article in the BACnet Europe Journal 32 03/20). The ÖBH has been using the BACtwin successfully for 4 years now, especially to achieve the goals of the Green Deal of the EU Commission, the targeted circular economy and climate-neutral building management.  Prof. Dr. Fritzenwallner also showed which further potentials arise from the use of the Internet of Things (IoT) and Long Range Wide Area Network (LoRaWAN) in connection with the BACtwin.

Prerequisites for successful use of BACnet in the real estate portfolio

In order for BACtwin to be used successfully by building owners and operators of their own and larger real estate portfolios, a number of prerequisites must be met. One of them is the interpretability of data, as Christian Wild, founder and managing director of ICONAG-Leittechnik already pointed out in his welcoming speech. Without interpretable data, there is no digitization, e.g., through the use of artificial intelligence (AI), as the diagram of the staircase to AI illustrates (see Fig.1).

The central key element of the BACtwin data model is therefore the user addressing system (BAS), often also referred to as the labeling system. Jürgen Hardkop (chairman of AMEV-AK BACtwin) and André Höhne (member of the aforementioned working group) came to this conclusion. Since existing BAS are not optimized for BACtwin and are not machine-readable, the AMEV-AK BACtwin has developed a new, powerful BACtwin-BAS (E) in continuation of VDI 3814 and presented it for the first time at the conference. This is machine-readable, user-friendly and future-proof. With the help of the BACtwin-BAS, machines can recognize and clearly interpret the data contents. Testing tools can validate the mass data 1:1 for planning, execution and operation. IT-based data exchange allows simple, fast and error-free handling in GA projects.

Future security without brand and manufacturer dependency can only be achieved if a building owner demands BACtwin. For this BAS and the BACnet profiles and object templates for the planned aggregates, building groups and plants of the space and plant automation must be specified and enforced over a BACnet requirement specification with advertisement and assignment, led Daniel Rörich out, which is responsible for the BACnet consultation of owners with the ICONAG.

A simple and very efficient BACtwin test procedure was presented by GA data pioneer Bernhard Ramroth of Excel-for-you. With his Excel-based testing tool, he showed how it is very easy to check during implementation and acceptance whether all automation stations have been set up in accordance with the BACtwin specifications, regardless of make and manufacturer. This also prevents the use of proprietary or even hidden properties.

Clear advantages for operations and management thanks to BACtwin

Even if the formulation of the BACtwin specifications means a certain amount of planning and the manufacturers of proprietary solutions will certainly not be cheering, the advantages on the part of the building owner are relatively clear. Christian Wild of ICONAG-Leittechnik showed how great the savings in engineering costs are on the part of the management and operating equipment when it reads the BACnet automation stations and, based on the data, can recognize which system it is and display the appropriate, standardized system images, as well as carry out alarm and timer configurations largely automatically - and this completely independently of the control brand used.

How the connection of building automation with the BIM model based on the BACtwin becomes possible was presented by Thomas Bender of pit-cup. With CAFM Connect, the CAFM Ring has launched such a standard. This allows the BIM profiles of facilities and components to be mapped as IFC data sets in IT systems, such as in the management and operating equipment or in the CAFM system. Technical building management processes, e.g. for maintenance, repair or energy management, can thus be implemented digitally between the different system worlds without any need for consultation.

Jürgen Keller of GEZE GmbH very clearly demonstrated the opportunities and advantages that arise for the integration of "ancillary trades" such as window or door control. The door or window system must, for example, provide data and functions for building automation, but also fire and burglar alarm systems and access control. Here, too, the BACtwin offers an optimal basis for standardization.

There are also significant advantages for shading. In particular to increase the user acceptance for the ever more complex becoming automation requirements, Dirk Mommaerts of the company Somfy specified. When using functions such as complex automatic wind monitoring, shade management and sun position tracking for the purpose of energy optimization and comfort enhancement, maximum transparency for the user and seamless connection to the building automation system are mandatory in large projects. The hurdles for both are significantly reduced by the BACtwin.

Prof. Dr. Rupert Fritzenwallner as an experienced building owner closes with an urgent appeal to the present building owners: Demand interoperable solutions for the automation stations (AS) and the management and control equipment (MBE) and do not let yourself be convinced by proprietary approaches with superficial arguments.

The Gutenberg Digital Hub e. V. is a broad alliance of business, science, and politics that is working together to meet the challenges of digital transformation. It is based in the old wine warehouse at the customs port in Mainz. Networking and exchange have been lived here since 2019. The spacious premises between the Rhine and the harbor basin offer room for meetings and events. A culture of exchange and learning from and with each other is to be lived here with the aim of making digitization in companies, the city and the region fit for the future.