© Martin Wagenhan

A cool solu­tion to an air condi­tioning chal­lenge

Europe’s leading online fashion plat­form Zalando has opened a 130,000 square meter logis­tics center in Lahr. Multi­Cross was respon­sible for the air condi­tioning. As if the tech­nical chal­lenge was not enough in itself, there was also a new EU effi­ciency direc­tive to contend with — with spec­i­fi­ca­tions that were anything but clear.


Spring 2017, Lahr

Men and women move through the aisles pushing little trol­leys. To the left and right there are shoe boxes and packs of hats, tee shirts, leather jackets, sports socks and brassieres. Every now and again they look at the monitor on their scan­ners, remove items from the shelves and take them to a conveyor system that trans­fers them to the pack­aging and ship­ping stations. Christof Krause lets an employee get past with his trolley and then takes a deep breath. “The air is good here. As we are able to program the amount of outside air in the building, we are in the process of exper­i­menting with it: How much outside air do we want to have, and how much is appro­priate from the point of view of effi­ciency? We don’t just rely on measured values, we follow our own noses as well.” Krause is Building Services Manager for a newly erected, 130,000 square meter logis­tics center belonging to the online fashion plat­form Zalando. The mega-ware­house is located in Lahr in the Black Forest, close to the Rhine and the border with France.

End of 2015, Emmerich

Christof Krause takes a satis­fied look at the air condi­tioning solu­tion. The company makes exacting demands for its working envi­ron­ment. (Photo | Martin Wagenhan)

530 kilo­me­ters down­stream where the Rhine forms the border with the Nether­lands, Frank Reimann, Managing Director of the Multi­Cross air condi­tioning company, pores over the construc­tion plans for the Zalando logis­tics center. It is Reimann’s job to make sure the temper­a­ture remains a constant 22 degrees Celsius at all times in every last corner of the new logis­tics center.

“Zalando demands very high stan­dards for the working envi­ron­ment and base their plan­ning on extremely tight toler­ances. When they say 22 degrees in summer and winter, absolutely every­where, that is exactly what they mean.” An enor­mous chal­lenge in the so-called order picking ware­house, for example, where the employees retrieve the items from the shelves: This ware­house consists of 175 rows on five levels that will be tightly packed with boxes of clothes in the future. “Air routing in this part of the building is partic­u­larly complex. And then there is the sheer volume to consider. We have to circu­late around a million cubic meters of air per hour.” The logis­tics center is supposed to be more or less finished in just under a year. The total planned construc­tion time is only around eight months; at the moment the site is a muddy field.

The air is good here. As we are able to program the amount of outside air in the building, we are in the process of exper­i­menting with it. Christof Krause, Building Services Manager Zalando in Lahr

At this point in time, Reimann’s main area of concern is the immi­nent intro­duc­tion of the Euro­pean Union’s 2016 ErP Direc­tive. This increases the effi­ciency require­ments for room air condi­tioning with effect from 1 January 2016. “The problem with such direc­tives is that nego­ti­a­tions go on almost right up to the last minute. And lots of impor­tant details are still not clar­i­fied by the time they come into force. Expe­ri­ence shows that the ques­tions really start once the direc­tive is actu­ally imple­mented.” Reimann feels as if he is stab­bing around in the dark: How is he supposed to supply Zalando with an air condi­tioning system complying to a stan­dard that he does not yet know for this fast-moving large-scale project?

Spring 2017, Lahr

Christof Krause proudly studies the so-called sorter, that auto­mat­i­cally pre-sorts the packs of clothes for mailing according to their desti­na­tion. The logis­tics center primarily serves Southern Germany, Switzer­land and France and will supply to customers on 15 Euro­pean markets in the future. “We place the pre-sorted containers in the yard and the DHL delivery trucks come and pick them up at night.”

Oper­a­tions are not yet running to full capacity. Six months after the start of the trial period, the logis­tics center is still being filled up, the mechanics are still working on some of the conveyor systems and 450 people currently come into work every day — over the medium term there will be more than 1,000. “To illus­trate the dimen­sions we are talking about: In the end we will have several million arti­cles here, from baby­wear to boots. The range is changing all the time. We are reck­oning with tens of thou­sands of outgoing pack­ages per day.”

Zalando has only existed since 2008. The start-up company soon over­took the old estab­lished busi­nesses and is now Europe’s leading online fashion plat­form with a turnover of around 3.6 billion euros in 2016. The logis­tics center near Lahr in the Black Forest is the fourth to be oper­ated by the company in Germany. The site used to be a Cana­dian air force NATO base. Since it was declared building land a few years ago, one logis­tics center has sprung up after another.

“There is a lot of compe­ti­tion for good workers in the region. So we have to offer an attrac­tive package. As well as being finan­cially inter­esting, the working condi­tions have to be excel­lent as well. And that is why we consider a constant pleasant temper­a­ture to be so impor­tant.” The company also tries to recruit workers from across the French border: Every­thing here is bilin­gual and every employee is given free instruc­tion in the other language.

End of 2015, Emmerich

While Frank Reimann is still scratching his head over the vague 2016 ErP Direc­tive, it occurs to him that Multi­Cross is a premium partner of ebm-papst. Premium part­ners are supplied with compo­nents and replace­ment parts more quickly and receive partic­u­larly inten­sive support for their projects. He can now make good use of this help, as ebm-papst was involved in the work on the various ErP Direc­tives right from the start. This time as well.

“The limit values were already spec­i­fied but the concrete criteria to be applied were simply not clear.” Is it permis­sible, for instance, to offset the high effi­ciency of an EC fan against the low effi­ciency of a partic­ular filter for the overall system to comply with the stan­dard? The wording was such that it was not even clear whether ErP 2016 was applic­able to logis­tics ware­houses like Zalando’s at all. “ebm-papst always gave me extremely sound appraisals, so that we had a reli­able basis for plan­ning the Zalando project.”

Fall 2016, Lahr

Frank Reimann is on site in the Black Forest. One crane lifts 25 heat recovery systems, each the size of a double garage, onto the 17 meter high roof of the building. Then there are the 84 gas engines for driving the instal­la­tions. The heat recovery systems above the so-called admin­is­tra­tion block with offices, kitchen, canteen and changing rooms, are fitted with partic­u­larly quiet-running and econom­ical RadiPac EC fans. Following the basic instal­la­tion work Frank Reimann watches over commis­sioning of the elec­trical system, the sensors and the data systems.

Frank Reimann enjoys the pleasant atmos­phere in the Zalando canteen. (Photo | Martin Wagenhan)

“Together with Siemens we devel­oped the EcoS­mart soft­ware. This provides our customers with a constant display of the crucial values such as temper­a­ture and CO2 concen­tra­tion and allows them to be controlled from a central computer.” The data are stored in a secure cloud. In the event of anom­alies, the Multi­Trend Viewer digital assis­tant devel­oped in conjunc­tion with ebm-papst sends a warning email to the applic­able tech­ni­cian, or Multi­Cross can take action in the form of remote main­te­nance. “With the trend toward smart building services and Industry 4.0, more and more customers expect this sort of system as stan­dard. So it is a great help that the EC fans can simply be actu­ated via MODBUS-RTU for example, and it is no problem to incor­po­rate them into an infor­ma­tion system.”

The limit values were already spec­i­fied but the concrete criteria to be applied were simply not clear. Frank Reimann, Managing Director of Multi­Cross

Spring 2017, Lahr

Christof Krause sits in one of the many confer­ence rooms. “For us at Zalando, such soft­ware systems are good interim solu­tions. We are in the process of creating central soft­ware for all our logis­tics centers, containing the data from all building services — not just from the air condi­tioning system. It is intended to be suit­able for all makes of equip­ment.” Zalando is aiming to make it easier to compare the values from existing large-scale ware­houses, such as power consump­tion in watts per article stocked.

In this way, the company hopes to achieve greater effi­ciency and obtain useful infor­ma­tion for new build­ings in the future. And the building services team will then only have to get to know one type of soft­ware. “For this project it is a great advan­tage that the systems from Multi­Cross can be readily inte­grated into the soft­ware. It is then very easy for us to pick out the items of data we consider to be impor­tant. At the same time, remote main­te­nance will still continue to func­tion. An ideal solu­tion for our purposes.”

Summer 2017, Lahr

The temper­a­ture in the Black Forest soars to 36 degrees Celsius. But the drinking water dispensers in the Zalando ware­house do not have to work any harder than usual. While all the customers are ordering sandals and bikinis, the Zalando employees at the logis­tics center are still comfort­able in long pants and solid safety shoes. 

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