Case Study:

Con­trol of the heat recov­ery sys­tem

Logo Laundry Bauer

Intu­itively con­trolled, sim­ply reg­u­lated

Wash­ing, dry­ing, iron­ing – the laun­dry Bauer from Großwech­sun­gen offers pro­fes­sional tex­tile clean­ing for pri­vate house­holds and com­pa­nies. As a mod­ern fam­ily busi­ness, the Thuringians have been rely­ing on heat recov­ery for a few years now. The heat recov­ery sys­tem is con­trolled by the mul­ti­func­tion con­troller (MFC) from HESCH. The intel­li­gent con­troller enables laun­dry experts to cre­ate com­plex automa­tion sequences them­selves, even with­out PLC and pro­gram­ming knowl­edge.

Using waste heat and gen­er­at­ing energy

Dry clean­ers and laun­dries have high energy require­ments: on aver­age, they spend a good 10 per­cent of their total costs on energy and water. This makes them one of the most energy-inten­sive sec­tors in the skilled trades. The major­ity – 85 to 90 per­cent – is required for the gen­er­a­tion of ther­mal energy, for exam­ple to heat the wash­ing lines, wash­ing machines, ironers and dry­ers, as well as for processes such as iron­ing and form­ing. This pro­duces waste heat that usu­ally escapes unused into the open air – a waste of resources that is nei­ther good for the envi­ron­ment nor good for the wal­let. Because waste heat is valu­able energy.


With a heat recov­ery sys­tem, it can be cap­tured and made usable again. This sig­nif­i­cantly reduces energy con­sump­tion and oper­at­ing costs.

Con­trol of the heat recov­ery sys­tem with­out PLC

The Bauer laun­dry in Großwech­sun­gen on the south­ern edge of the Harz Moun­tains also works con­tin­u­ously to opti­mise processes and reduce costs. This mod­ern fam­ily busi­ness col­lects, deliv­ers and processes in-house and rental linen for hotels, guest­houses, restau­rants, house­holds, pub­lic insti­tu­tions, busi­nesses and nurs­ing homes.

To increase effi­ciency, the Thuringians decided some time ago to install a heat recov­ery sys­tem. There were plenty of such sys­tems on the mar­ket. But vir­tu­ally all man­u­fac­tur­ers insisted on using their own pro­gram­ma­ble logic con­troller (PLC).

How­ever, these PLCs were too expen­sive and inflex­i­ble for my pur­poses.

Lothar Bauer (owner)

Maid with freshly laundered towels
Wash­ing, dry­ing, iron­ing - the laun­dry Bauer from Großwech­sun­gen offers pro­fes­sional tex­tile clean­ing for pri­vate house­holds and com­pa­nies.

As a trained elec­tri­cian, he is famil­iar with the sub­ject mat­ter, but has no spe­cial pro­gram­ming knowl­edge – but with­out this you won’t get very far with a PLC.

"There is a con­stant need for improve­ment in my laun­dry. There­fore, I must be able to con­stantly expand, con­trol, mon­i­tor and reg­u­late."

Lothar Bauer

“I would like to do this myself with­out hav­ing to hire a PLC pro­gram­mer every time,” says Lothar Bauer.

So Bauer set out to find a plant man­u­fac­turer who would only sup­ply him with the heat recov­ery tech­nol­ogy (with­out a PLC) and an intel­li­gent con­troller that would give him the free­dom he wanted.

Less is more

Dur­ing his Inter­net research, he came across the mul­ti­func­tion con­troller (MFC) from the HESCH com­pany and was imme­di­ately enthu­si­as­tic:

With the MFC, you can cre­ate, opti­mize and mon­i­tor sequence con­trols your­self - with­out hav­ing to have a degree in pro­gram­ming.

Lothar Bauer

“This is exactly what I was look­ing for,” said Lothar Bauer.
The MFC is mod­u­larly expand­able and offers sim­ple com­mis­sion­ing, intu­itive oper­a­tion and a wide range of com­mu­ni­ca­tion inter­faces (PROFINET, PROFIBUS, Mod­bus, CAN bus, HPR bus). In addi­tion, an exten­sive func­tion library with over 100 ready-made func­tions is avail­able. These can be assem­bled on the PC sim­ply by drag & drop to the desired process flow. Pro­gram­ming knowl­edge is not required. This saves time and costs.

Screenshot EasyTool MFC
In the graph­i­cal edi­tor (Easy­Tool MFC), the user wires the fin­ished func­tion blocks with­out requir­ing any pro­gram­ming knowl­edge.
Heating at the heat recovery unit
The mul­ti­func­tion con­troller ensures that the two heat exchang­ers work effi­ciently. For this pur­pose, it mea­sures the tem­per­a­tures at sev­eral points in the process and con­trols (opens / closes) the 3-way valves and cir­cu­la­tion pumps.

All-rounder for all con­trol and mon­i­tor­ing tasks

In the mean­time, the MFC from HESCH has been in use in the Großwech­sun­gen laun­dry for over two years. There he con­trols and mon­i­tors the com­plete heat recov­ery sys­tem.


It ensures that the two heat exchang­ers work effi­ciently and ensures that there is always enough hot water for pro­duc­tion. In addi­tion, he man­ages the sup­ply of heat­ing energy to other com­pany build­ings (din­ing room, chang­ing rooms, offices) and the adja­cent res­i­den­tial build­ing. For this pur­pose, the MFC mea­sures the tem­per­a­tures at sev­eral points in the process and con­trols (opens / closes) the 3-way valves and cir­cu­la­tion pumps. The sys­tem pres­sure is also mon­i­tored.

“The data log­ger func­tion is also very inter­est­ing for us,” Bauer reports. The MFC records the heat curve over the entire pro­duc­tion day. The data can be saved locally and viewed and ana­lyzed clearly in tab­u­lar form.

"This gives me an overview of the processes at all times and allows me to make fur­ther opti­miza­tions based on the data."

Lothar Bauer

Thanks to its numer­ous com­mu­ni­ca­tion inter­faces, the MFC can be eas­ily inte­grated into all sys­tems and allows access to the data from any­where.

Buffer tank as part of the heat recovery system
In the Bauer laun­dry, the MFC from HESCH con­trols and mon­i­tors the com­plete heat recov­ery sys­tem. Sur­plus heat is tem­porar­ily stored in the buffer tank

Tak­ing the wheel into your own hands

The HESCH experts at the Bauer laun­dry were on hand from the very begin­ning to pro­vide sup­port and advice.

"The tech­ni­cal sup­port pro­vided by HESCH is really excep­tion­ally good."

Lothar Bauer

“After installing the heat exchang­ers, pip­ing and wiring, we worked together to build the con­trol sys­tem piece by piece. Actu­ally, we’re not really done with that even now. We have new sug­ges­tions for improve­ments all the time and are still in con­stant con­tact,” reports Bauer.


Ser­vice is a top pri­or­ity at HESCH. Detailed instruc­tion in the func­tion­ing of the MFC as well as sup­port in “pro­gram­ming” are there­fore part of the scope of ser­vices for the automa­tion spe­cial­ist.

Control of the heat recovery system
The dis­play of the mul­ti­func­tion con­troller gives an overview of the cur­rent tem­per­a­tures. Set­tings can also be made here.

Mod­u­lar con­cept with many options – not only for con­trol­ling the heat recov­ery sys­tem

Due to the local con­di­tions, an exten­sion mod­ule is used in the Bauer laun­dry in addi­tion to the mul­ti­func­tion con­troller. The Field­bus Cou­pler HE 5813 con­nects the mod­u­lar Process I/O HIMOD Sys­tem with a Mod­bus RTU net­work and enables an appli­ca­tion also out­side the con­trol cab­i­net.

Thanks to its own intel­li­gence, the multi-chan­nel I/O mod­ule is able to pre-process the incom­ing sig­nals from the tem­per­a­ture sen­sors. This relieves the sys­tem con­trol. The HIMOD exten­sion is installed in the pro­duc­tion area, the main con­trol sys­tem is located in the boiler house 100 meters away. Both are con­nected via a data line.
“This intel­li­gent field­bus sys­tem is of great advan­tage to us,” says Bauer. “It allows us to install all the con­trol relays in the pro­duc­tion area with­out hav­ing to run any more wires.” The multi-func­tion con­troller from HESCH is not the first con­troller in the Thuringian laun­dry. Sev­eral PLCs from dif­fer­ent man­u­fac­tur­ers are already in use. But the MFC is the first con­troller that has con­vinced Bauer all along the line:

"It is easy and intu­itive to oper­ate, intel­li­gently net­worked, and can be flex­i­bly changed and expanded at any time. It's per­fect for us. I can only rec­om­mend it to any laun­dry busi­ness."

Lothar Bauer

There is also another, pos­i­tive effect: Bauer reck­ons with a sav­ings poten­tial of at least 20 per­cent in energy con­sump­tion.

Are you inter­ested in a prod­uct demon­stra­tion?

Write to us or give us a call. We will be happy to arrange an appoint­ment with you.

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