Efficient Heating Technology at 170 Meters Height
How do you heat a building that soars 252 meters into the sky – and maintain a comfortable climate at 170 meters, even in freezing winter winds?
The Danube Tower, Austria's tallest structure, presents extraordinary technical challenges. To ensure visitors at the rotating tower restaurant and café can enjoy panoramic views of Vienna even during icy winters, a particularly innovative and well-thought-out heating solution was required. With Hoval as a partner, this challenge was successfully mastered.
Technical Challenges at High Altitudes
With several hundred thousand visitors annually and a total height of 252 meters, the Danube Tower is not only a tourist magnet but also a feat of engineering. The modernization of the heating system for the rotating restaurant at 170 meters and the tower café at 160 meters posed high demands on planning and technology.
Hoval: Tailor-Made Solutions for the Danube Tower
The overhaul of the heating system, which had reached its limits, began in 2017. Two powerful Max-3 gas boilers from Hoval were installed to meet the increased demands of the new gastronomic spaces. The heating capacity was increased from an original 450–500 kW to 650–700 kW.
One of the key aspects of the planning process was pressure balance. At a height of 165 meters, a minimum pressure of 1.5 bar is required, necessitating an output pressure of 18 bar in the boiler room. To achieve this, a system with heat exchangers was integrated to transfer energy into separate circuits. This solution also ensures operational reliability and flexibility.
Comfort on Rotating Platforms
Special attention was paid to heating the two rotating platforms in the restaurant and café. An innovative baseboard heating system with warm air ensures visitors can enjoy Vienna’s views even in winter. Warm air is channeled from the tower’s center using a new brush technology into rotating floor ducts. A second heat exchanger at the top of the tower heats the air. Thanks to the robust Max-3 boilers, which provide a constant high flow temperature of up to 100°C, warm air remains at 80°C even on cold days. This is sufficient to maintain a cozy atmosphere, even in winter.
Comprehensive Support by Hoval
Hoval supported the project from the initial planning to installation and has managed maintenance since the system's commissioning in 2017. The intelligent TopTronic E control system adjusts heating output to demand, while online connectivity allows for remote adjustments. Additionally, a dedicated spare parts warehouse was set up for the Danube Tower to ensure optimal service.
With Hoval’s heating technology, the Danube Tower is well-equipped for the years ahead. The tailor-made solution combines technical sophistication with reliability, ensuring this iconic Viennese landmark offers visitors a comfortable experience, no matter the weather.
