Making fine wine a safe prospect

To protect his employees, Michael Braun of the Beckstein winegrowers’ cooperative replaced his old ventilation system with a new one. The system reliably draws dangerous fermentation gases outside, while also creating more room and peace for wine production.


It’s high season at the winegrowers’ cooperative in Beckstein, located in the Main-Tauber district of Baden-Württemberg. Michael Braun, managing director of Becksteiner Winzer, walks through the vineyards and takes samples of different grape varieties. They decide which grapes will become wine next. Since its foundation in 1894, the winegrowers’ cooperative with its 21 associated communes has grown to a vineyard area of 250 hectares, and the choice is correspondingly large.

In the end, a Weissherbst and a Silvaner are chosen. “We deal with wine here – a ‘luxury good’ designed to be fun and make our lives more enjoyable,” says Braun, who turned his hobby into a profession eight years ago. “We produce around 2.3 million liters per year. To ensure that every drop in every glass is outstanding, we work with very high quality standards. This also applies to the safety of my employees.”

Since its founding, the winegrowers’ cooperative has grown to a vineyard area of 250 hectares, and the selection is correspondingly large. (Photo | Lukas Zwiessele)

Ventilation system against fermentation gases

After the harvest, the grape juice must ferment so that the fructose is converted into alcohol. Beckstein’s fermentation cellar has room for over 160 fermentation tanks holding 4 million liters. The starting signal for fermentation is given by the addition of yeast. However, one waste product is fermentation gas, carbon dioxide. This makes the process dangerous at the same time: “We have an extra ventilation system in our fermentation cellar for this purpose,” explains Michael Braun. “It draws off the fermentation gas and ensures that our employees feel comfortable while working and are supplied with sufficient oxygen.” This is because the gas is heavier than oxygen and settles unnoticed on the floor of the cellar. If the concentration increases, employees are put at risk. The fermentation gas extraction system on the cellar floor ensures safety.

I knew we could be even better and more efficient with a new system.

Michael Braun, managing director of Becksteiner Winzer

But it was getting on in years: “I knew we could be even better and more efficient with a new system,” says Braun about his decision to retrofit. “The old system ran 365 days in peak operation, but in fact our high season only lasts about 40 days a year. That alone indicated to me huge potential for savings as well as relief for the ears of the employees who work there every day.” The decisive factor was a fan replacement campaign by FGK, Germany’s professional association for buildings and indoor air quality, with an associated funding program for upgrading to more energy-efficient fan systems in non-residential buildings. “We received a notice of a 40 percent grant for the retrofit,” says Braun. “That was a nice bonus that supported our decision.”

Flexible airflow, high efficiency

Then things got underway. Systemair GmbH, local supplier for efficient ventilation systems, took a closer look at the system: “It was running a belt-driven axial fan from the early 1970s,” explains Harald Rudelgass, Associate Director Technical Regulatory Affairs at Systemair and head of the project. “According to our readings, the system had an efficiency level of about 60 percent. So we were able to confirm to Mr. Braun that with cutting-edge EC technology, things are much better these days.”

Rudelgass opted for a ventilation solution with two ebm-papst RadiCal fans with EC technology installed in Multiboxes from Systemair. “With the new RadiCal, we had exactly the large size 710, which was a good fit here, as well as state-of-the-art EC motors with an efficiency of 90 percent – which then also has a positive effect on overall system efficiency,” he says. “Our Multiboxes allowed us to make the airflow more flexible, redirecting it 90 degrees from the previous straight direction.”

Our Multiboxes allowed us to make the airflow more flexible, redirecting it 90 degrees from the previous straight direction.

Harald Rudelgass, Associate Director Technical Regulatory Affairs at Systemair

This was a crucial advantage, as the winegrowers’ cooperative was not only swapping something old for something new, but also replacing a large system with a small one. Where once there had been the large axial fan, complete with exhaust chimney, space was freed up with the current RadiCal fans, which discharge air to the outside under the roof at a 90-degree angle: “We gained valuable production space with the retrofit, which will help us grow even further as a cooperative,” comments Michael Braun on the outcome. Where air used to be piped out, new bottling lines now pour wine into bottles.

The winegrowers’ cooperative produces approximately 2.3 million liters of wine per year. (Photo | Lukas Zwiessele)

Retrofit ensures reliability

And in terms of safety, too, the retrofit had its good points: The solution with two fans arranged in parallel protects the system against failures. If one of the two fails, the other can keep the gas concentration low enough to be safe for the employees. Efficiency is ensured not only by the EC technology but also by the precise control on two floors. The system only provides full power when the high season requires it. An additional CO2sensor helps and automatically turns the fans down when the appropriate air quality is achieved.

The ventilation system is 15 dB(A) quieter, as desired, and thanks to the RadiCal’s backwards-curved impellers, there is an extra advantage in terms of cleanliness: “On the old fan, we clearly saw that dust particles were also sucked in during operation,” explains Harald Rudelgass. “The backward-curved blades have the appeal of cleaning themselves by running in the opposite direction, so nothing gets stuck there.” This in turn ensures a long service life.

7500 kWh saving per year

“We are now in the middle of the season in which the fermentation gases are produced,” says Michael Braun. “Everything has been completed on time and we are very satisfied with the system’s operation. It’s so quiet that we almost don’t notice any of it.” The theoretical savings of 30 percent have already been achieved. At an estimated operating time of 2,500 hours per year, this corresponds to around 7500 kWh. The savings are likely to be even greater. But Braun and Rudelgass won’t see that until the season is completely over.

In ebm-papst, we have found a reliable partner for ventilation technology for more than two decades.

Harald Rudelgass, Associate Director Technical Regulatory Affairs at Systemair

Until then, another retrofit for a second fermentation cellar is already being planned – once again jointly with Systemair and ebm-papst technology: “In ebm-papst, we have found a reliable partner for ventilation technology for more than two decades,” says Harald Rudelgass. “We have been purchasing ebm-papst fans for several product generations due to their EC technology and are very excited about what’s to come in the future.”

Required fields: Comment, Name & Mail (Mail will not be published). Please also take note of our Privacy protection.