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.”

Harald Rudel­gass, Asso­ciate Director Tech­nical Regu­la­tory Affairs at Systemair, and Michael Braun, Managing Director of Beck­steiner Winzer, worked closely together on the retrofit. (Photo | Lukas Zwies­sele)

A venti­lation system in the cellar extracts fermen­ta­tion gas and ensures that employees feel comfort­able while working and are supplied with suffi­cient oxygen. (Photo | Lukas Zwies­sele)

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.”