Half a century of expertise and experience in tunnel ventilation systems

Company focus is mainly on renovation projects in coming decades

For some 76 years, NOVENCO Building & Industry has been considered a specialist in innovative ventilation systems. Products manufactured to the highest standards in motherland Denmark and known for their uncompromising quality. Not only because of their high efficiency and low noise level. NOVENCO products and systems are also at a very high level in terms of durability. It is precisely this fact that makes the company's product solutions so suitable for the Dutch market, an area in which the necessary tunnel renovation projects are scheduled for the coming decades...

NOVENCO's ventilation systems can be found all over the world. Also in the Netherlands, where the originally Danish company has been active since the 1970s. While in the early days the emphasis here was on the production of ventilation systems for the shipping industry, it gradually shifted to the development and manufacture of high-quality tunnel fans and systems. As a result, over the years NOVENCO Nederland has supplied a large part of the national road and rail tunnel stock with thrust fans. Indispensable components that provide ventilation under normal conditions (also in case of traffic jams) on the one hand and in case of calamities, such as fire, on the other. In the first application, the tunnel air is ventilated in the direction of travel via the thrust principle. In the other case, the tunnel fans ensure that people can leave the tunnel tube quickly and safely by keeping escape routes smoke-free.

Renovation Battle

The Dutch landscape is home to quite a few underwater and land tunnels. Artworks many of which, it turns out, will be subject to a thorough overhaul in the relatively near future. "In the next 10 to 15 years, more than twenty tunnels will be renovated in the Netherlands," said Ruud van Beek, general director of NOVENCO Netherlands, which serves the Dutch market from Bergschenhoek with about 35 employees. "So it's not surprising that, as a reliable partner for new construction and renovation of tunnels, together with our clients, we are going to focus mainly on this discipline. A discipline that is completely different from new construction. Certainly when it comes to replacing or not replacing existing equipment and systems with new, more durable components. This specific matter often leads to discussions. Because when do you do it right? On the one hand, we all want to reuse and be circular. But we also want the newly installed technology to be sustainable, long-lasting and with a low CO₂-footprint. As a participant in the COB, the Center for Underground Construction (see also www.cob.nl), we regularly engage in dialogue with our clients and other market players on this subject and try to find solutions together. In addition, as a participant in various working groups, we contribute to ongoing discussions about sustainability, circularity, energy efficiency and reuse of materials. We have a keen eye for the world of tomorrow. In doing so, we make use of our archive, which contains very valuable material and information about the ventilation systems of many tunnels built in the Netherlands since the 1970s."

Space-saving

Mountain tunnels with a round tunnel profile are the norm in most countries, but in the Netherlands we mainly encounter underwater tunnels and land tunnels with a rectangular profile. That specific shape also means that the space to install fans in an existing tunnel is a lot more limited. "This is also why we have developed a series of space-saving rectangular design fans with minimal installation height," Van Beek explains. "Not only does this invention save 20 centimeters in height compared to a round fan, its efficiency is also a lot higher. The fans are very efficient, so you can generate more thrust per kilowatt." And what is further noteworthy: by using these height savers, a smaller ceiling height is also sufficient. Something that results in huge cost savings during tunnel construction. Talk about working sustainably... Furthermore, NOVENCO developed the ZerAx^®, the most efficient fan in the world. This innovative ZerAx^®-design has also been applied to tunnel entrance fans, making them as much as 20% more efficient. 

Certified ventilation system for a greener and safer world 
With the ZerAx^® RWA fan system with frequency control gives NOVENCO the answer to the demand for more efficient, sustainable (tunnel) ventilation systems. In the form of, among others, the ZerAx^® HT, the world's most efficient and quietest certified RWA fan, the company takes another step toward a greener and safer world. "The EN 12101-3:2015 certification allows the use of speed-controlled RWA fans in case of fire," said Van Beek. "To this end, the RWA fan in combination with the frequency converter used must be tested and certified at high temperature by an independent body. This has been done. The full range of reliable, energy-efficient ZerAx^® axial fans from NOVENCO have been tested and certified by the MPA in Braunschweig as RWA fans in combination with Danfoss VLT^® frequency converters."

Key features of NOVENCO tunnel fans: 
Non-reversible or 100% reversible versions
Tested and certified smoke control systems up to 400 °C for 2 hours
High efficiency and low noise levels
Special deflectors for optimum plant efficiency
High thrust at minimum installation height

A welcome total package
During the realization of the optimal tunnel ventilation solution, NOVENCO offers a complete package of services.
Design of tunnel ventilation and smoke control systems
Deterministic and probabilistic system calculations for risk analysis
Project-specific product alignment
Project supervision from design to handover to client
FAT (Factory Acceptance Test), SAT (Site Acceptance Test) and airside support for system commissioning

Case study
Lack of space, reduced maintenance in the tunnel, service life and noise: these were all pain and concerns when renovating the tunnel ventilation of the A73 tunnels Roer and Swalmen. The main goal during this project was to place no or minimal fans in the tunnel in order to prevent collision damage. The ideal solution was found through the placement of fans at the entrance and fans at the exit for reversibility. 
Because the NOVENCO ZerAx applied^® input fans 20% generate more thrust per kilowatt, a smaller diameter can still provide sufficient thrust within the power envelope. To ensure a 30-year service life, the ZerAx^® input fans manufactured from stainless steel 316 L. Also, the recyclability of the ZerAx^® 98% (this was determined and reported by Stena Recycling). The result: in collaboration with Croonwolter&dros, NOVENCO was able to provide a suitable and sustainable solution for the renovation of the A73 tunnels Roer and Swalmen.