© 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).