High School Wendelstein, Wendelstein, Germany, 2013

Gymnasium_WendelsteinWendelstein high school is characterized by its trend-setting energy concept, which relies on renewable energies like geothermal heat and solar energy, on corresponding construction building physics, and the required intelligent building and HVAC automation producing low energy consumption. There were specific efficiency targets. With a limited thermal energy need of 40 kWh/m² (3.7 kWh/ft²) the school matched the standard of a low-energy house, being only scarcely above consumption levels of a passive house. The loss of heat was reduced to a minimum [specifically: 0, 30 W/m²K (0.05 BTU/hr/ft2/°F)] due to an appropriate cladding. Two simple figures only, but standing for ambitious goals.

Without comprehensive system integration and the consequent utilization of standardized communication protocols for interconnection of the systems, a concept like this cannot be implemented economically. In the Wendelstein project a LonMark System (CEA-709) is applied as integrative communication technology and all systems like HVAC, energy data acquisition, or DALI lighting control are integrated. Approximately 1,000 nodes perform their tasks reliably in the building automation network of the high school. Numerous other hardware components are integrated via DALI, Modbus and BACnet. The system integration adapted to the building and its utilization allows a secure and energy efficient operation of the facilities engineering systems.

Innovative Class Room Ventilation with L-IOB I/O Controllers

The energy concept did not only aim at savings but also at a good indoor climate. Controlled ventilation of each class room plays a decisive role at it. Decentralized Trox ventilation devices with integrated heat recovery (Schoolair-V) provide the necessary fresh air in the rooms. Automation of the ventilation devices is managed with integrated, freely programmable L-IOB I/O Controllers by LOYTEC communicating on the LonMark TP/FT-10 channel. Perfectly adapted to the specific requirements of the project, the L-IOB I/O Controllers inside of the almost 120 Schoolair-V ventilation devices provide a comfortable climate in Wendelstein high school.

L-INX Automation Servers Take on Tasks in Building Automation

For automation of the sun blinds, control of the concrete core cooling, demand-based lighting control of the big entrance hall, corridors and the exterior, freely programmable L-INX Automation Servers are deployed. Here the extremely short program cycle times (down to 10 ms) are advantageous with the resulting quick response time for switching the light and synchronic operation of the sun blinds. Simultaneously the L-INX Automation Servers act as gateways for the Modbus integration of energy meters into the CEA-709 network.

Constant Light Control with L-DALI

Up to 2,000 DALI lamps are connected to L-DALI Lighting Controllers. The controllers manage constant light control in the class rooms and are able to regulate the two lighting zones (one at the window side, one at the corridor side) independently from each other. DALI multi sensors by Osram are incorporated into constant light control. The integrated gateway function of the L-DALI Lighting Controllers sends data from the multi sensors to be displayed as network variables. This way data is available for the entire building automation system. This important data is utilized in various overlapping building applications.

Operation and Monitoring with L-VIS Touch Panels

L-VIS Touch Panels are used in the sports gymnasiums by both pupils and teachers for lighting control, and for stationing of the basketball hoops, still rings and the separating curtain walls. The school building engineer uses L-VIS for regulation of the lamps in the big entrance hall and in the corridors as well as for monitoring all windows and door positions in the building.

Data Monitoring for Optimization of Energy Consumption

The facility management of the school’s owner, the county of Roth, is responsible for continuous acquisition and evaluation of system and consumption data. This helps in analyzing the high schools’ energy fluctuations and monitoring the systems. The aim is to optimize energy consumption permanently and to quickly detect error sources in case of deviations. Consumption data is provided by electricity meters, heat meters and water meters. Meters using CEA-709, Modbus/RTU interface and pulse counters are used. L-IOB I/O Controllers provide data from the Schoolair devices, distributed L-DALI Lighting Controllers provide consumption data from the DALI lighting system, and L-INX Automation Servers gather energy data of the solar systems via Modbus TCP.

LonMark System

All network nodes on LonMark TP/FT-10 channels are connected via L-IP Routers to the IP network (LonMark IP-852). Due to this network system the operator can access the building automation system and respectively the installed network nodes, local or remote at any time. 
Within the LonMark System the installed L-INX Automation Servers, L-GATE Gateways and L-DALI Lighting Controllers integrate other devices utilizing communication protocols like BACnet, Modbus and DALI and so provide seamless exchange of data between the different systems.

During a construction period of two years only the county of Roth erected the three floor concrete steel construction of high school Wendelstein with a gross floor area of 12,500 m² (134,548 ft²) for up to 800 students. It is considered the most modern high school in Bavaria and already has won several awards.


Photos © Oliver Heinl, Fuchs und Rudolph Architekten

Interesting Facts

Devices: LINX-100, LINX-110, LGATE-900, LIOB-180, L-DALI, L-IP, L-VIS

Location Wendelstein, Germany
Number of Nodes
ca. 1,000
Topology CEA-709
Companies involved
NV-Connection, Raimund Hoyer
LOYTEC Components 2x LINX-100,
4x LINX-110,
3x LIP-33ECTB,
3x LIP-3333ECTB,
3x L-GATE-900,
118x LIOB-180,
29x LDALI-3E101,
11x LDALI-3E102,
4x LDALI-3E104,
3x LVIS-3E100,
1x LVIS-3E115