Smart Building

Sustainable automation in heritage buildings

Author: Henning Meyer, Building Automation Consultant, EnOcean GmbH
Issue 04-2024: read all articles online read as pdf

Modern building control technology is a central element of energy- and cost-efficient climate control in buildings. Particularly in heritage buildings, sustainably functioning building automation requires a great deal of sensitivity when it comes to choosing the right products and technologies. When modernizing the building services and improving the air conditioning in the Bellevue Hotel Dresden, those responsible also relied on products that use EnOcean energy harvesting technology.

Modernizing building services and efficiently designing room air conditioning

The Bellevue Hotel Dresden looks back on an eventful history. Built between 1723 and 1727, it is the only remaining building complex on the famous Große Meißner Gasse. In recent history, it was the scene of significant events, including the German reunification (1989) and the G8 summit (2007). The new owner of the now heritage-listed hotel with 328 rooms decided to comprehensively modernize the building services. Particular focus lay on the manual regulation of the room temperature via the radiators and the outdated fan convectors. These were also in operation when guests were absent and had been proven to lead to energy losses. Arndt Badsanierung GmbH & Co. KG was awarded the contract for the installation of energy- and cost-efficient room air conditioning solutions. For the implementation, the company relied on room thermostats and radiator valves from Thermokon’s “EasySens” wireless system, which makes use of the EnOcean energy harvesting solution.

Integrating room air conditioning into the building management system

“The key to the energy- and cost-efficient design of the room air conditioning was the decision to equip it with state-of-the-art technology and integrate it into the building management system. As a result, the hotel’s technical service is now able to centrally control all room statuses and device functions,” says Mario Arndt, Managing Director of Arndt Badsanierung. To ensure resource-efficient operation, the fan coils were replaced with units with energy-efficient ec motors and low noise levels. The radiators and fan coils were linked to the presence detector. They are now controlled depending on the occupancy of the rooms. If the presence detector detects that a room is empty, a defined temperature is activated via the building management system. If a guest is present, on the other hand, the system enables individual control by the guest.

The Radio Room Controller JOY Fancoil simplifies the precise control of room temperature and is essential for sustainable building automation
The Radio Room Controller JOY Fancoil facilitates precise control of the indoor climate ©Lichtwerk Christian Plaum

“The use of high-quality sensor systems from Thermokon, in particular the combination of the JOY room thermostat with Modbus interface and the EnOcean-based energy self-sufficient SAB+ electronic radiator valves and SRW03 wireless window contacts, was essential for the successful automation of the heating technology,” emphasizes Timon Deisel, Thermokon Sales Manager Germany. With its flat housing, scratch-resistant acrylic glass surface and backlit LCD display, JOY blends in with the look of the room and makes controlling the indoor climate simple and precise. Communication with the building management system takes place via the integrated Modbus interface. Networking with the SAB+ radiator valve and the SRW03 window contact is radio-based and therefore also wireless.

Energy harvesting reduces installation and operation costs

Thanks to their solar cells and intelligent energy harvesting, the two solutions minimized installation work at the Hotel. By eliminating the need for regular battery changes, they also reduce the hotel’s personnel costs during operation. Also the energy savings during ventilation are impressive. Because as soon as the status monitoring of the window contact detects an open window, the room air conditioning is automatically deactivated.

The heat valve SAB+ and the window contact SRW03 are based on Energy Harvesting Technology
The SAB+ radiator valve and the SRW03 window contact are based on energy harvesting technology ©Lichtwerk Christian Plaum

Added value through energy harvesting, battery-free wireless switches and window contact sensors

“This project demonstrates the benefits of our energy harvesting technology and our sensor products. The use of alternative energy sources from the environment, such as temperature, movement, and light in this case, as well as our integrated battery-free wireless switches and window contact sensors, which provide information about open windows, for example, have contributed to increasing the energy and cost efficiency of the Bellevue Hotel Dresden,” summarizes Markus Florian, CCO at EnOcean. Savings were also achieved during the modernization by reducing downtimes, saving on cabling and through external pre-assembly of the components. In addition, Thermokon worked with Wago to develop a concept based on ready-to-plug-in cabling of the components via Winsta-Box. That way, commissioning in the rooms could be carried out quickly, safely, and error-free via plug & play.

Solutions for building automation in existing buildings

The German Building Energy Act 2024 aims to promote the use of renewable energies in the building sector and also to end the use of fossil fuels by 2045. Sustainable building automation in listed buildings poses a particular challenge in this regard. Especially when it comes to anchoring energy- and cost-efficient room air conditioning. Working in a goal-oriented, responsible manner with all partners is essential for such projects. The modernization of the building services at the Bellevue Hotel Dresden has demonstrated that. Together with its partners, EnOcean will continue to support owners and tenants of houses, buildings and industrial facilities. High-quality products and sustainable IoT solutions help retrofitting and optimizing existing buildings.

All pictures with courtsey of Lichtwerk Christian Plaum