Acquiring new customers is a tough job. However, it has been daily reality for Reiner Riedle and Raphael Mayer since they estab­lished their own company two years ago. AIRnorm GmbH, based in Engen im Hegau in southern Germany, special­izes in venti­lation and air condi­tioning, process air filtra­tion, and retro­fits for existing systems. Riedle and Mayer are enthu­si­astic about what they do and, with their company, have fulfilled their dream of promoting inno­v­a­tive and effi­cient venti­lation and air condi­tioning tech­nolo­gies.

Along­side the patented two-stage adia­batic cooling process that is their favorite tech­nology, retro­fitting existing systems is an impor­tant part of the company’s port­folio. That is what Reiner Riedle was pitching to a well-known compo­nent manu­fac­turer near Tuttlingen in October 2023. “Our contact there was concerned about three areas,” says Riedle of that meeting. “Cooling the produc­tion building, aerosols –‎ and thus air quality – and a general assess­ment of the system.”

More effi­ciency, less costs: Retrofit

Retrofit of fans with ebm-papst

Retro­fitting existing fans in venti­lation and cooling systems with effi­cient EC fans and demand-based oper­a­tion can save up to 60 % energy and costs – and protect the envi­ron­ment at the same time.

Find more infor­ma­tion here

More effi­ciency, less costs: Retro­fitting fans with ebm-papst

This was no problem for all-rounder Riedle. He reviewed the entire venti­lation system in Hall 3, one of the customer’s five produc­tion build­ings. Analysis of the data showed that a retrofit would yield energy savings of around 30 percent. The customer was inter­ested because Riedle’s analysis and calcu­la­tion revealed that the neces­sary invest­ment would be amor­tized in less than four years. After speaking with the company’s manage­ment, a more detailed presen­ta­tion of the retrofit project was requested.

System avail­ability has priority

Riedle and Mayer proposed replacing the existing IE4 motors (Inter­na­tional Energy Effi­ciency Class 4), each of which powered a centrifugal fan in the exhaust and air intake housing via a V-belt, with FanGrids consisting of five EC fans from ebm-papst. The back­ward curved RadiPac centrifugal fans are mounted in specially produced aluminum frames. These assem­blies, known as FanGrids, are usually produced in such a way that more fans can be added quickly if required. In addi­tion to the calcu­lated energy savings, Riedle and Mayer high­lighted the redun­dancy provided by several fans compared with just one single fan.

“If there is a problem with the fan’s impeller or housing, replace­ment parts are not quickly avail­able. Depending on the year of construc­tion, their supply takes three to four weeks at least. This means losing the entire output if there is one defec­tive fan in the system,” says Riedle, explaining the disad­van­tage. “In a FanGrid, this lost output is simply made up by the other four fans and the venti­lation system can continue oper­ating as required.”

A possible outage of the venti­lation system? This trig­gered alarm bells for the customer. The exhaust air from the machine tools in Hall 2 is directly connected to the venti­lation system. Failure of this system would there­fore result in a produc­tion stop­page because the oil aerosols produced by the machine tools could no longer be extracted and the building would be “flooded” with oil mist within just a short time. There was an urgent need for action. The customer decided to defer upgrading the venti­lation system in Hall 3 and commis­sion the Hall 2 retrofit from AIRnorm.

Three-and-a-half days for more safety

The retrofit was carried out during the summer vaca­tion. “Since the customer was closing for a week anyway, it was possible to shut down the system,” recounts Riedle. “Removing the old drive motor was a chal­lenge,” explains Mayer. “It weighed 320 kilo­grams and had to be lowered safely from a height of two-and-a-half meters.” The customer provided suit­able lifting vehi­cles for this purpose.

„We prepared the system design, discussed it with Breuell & Hilgen­feldt and then had the whole thing veri­fied by ebm-papst’s FanScout design program.“

Reiner Riedle, General Manager AIRnorm GmbH

In plan­ning the project, Reiner Riedle and Raphael Mayer were supported by Breuell & Hilgen­feldt, the ebm-papst sales partner for retro­fits. “This collab­o­ra­tion was a real success,” enthuses Riedle. “I have rarely expe­ri­enced the level of coop­er­a­tion we received from Dieter Hilde­brandt.” And Raphael Mayer adds: “We prepared the system design, discussed it with Mr. Hilde­brandt, and then had the whole thing veri­fied by ebm-papst’s FanScout design program. We then set about choosing the fans.” The perfect solu­tion was the RadiPac C, an EC centrifugal fan char­ac­ter­ized by high effi­ciency, compact design, and plug & play capa­bility for use in FanGrids.

Hand in hand for the perfect oper­a­tion

In order to install the RadiPac, the AIRnorm special­ists had the neces­sary aluminum brackets manu­fac­tured. One reserve space in each of the FanGrids means an addi­tional fan can be installed quickly and easily if required. As the customer has only one access point to the fan chamber, Riedle and Mayer planned a remov­able segment that also gives access to the fan from the intake side. “This makes it much easier to perform main­te­nance work such as cleaning the heat exchanger register,” explains Riedle.

In addi­tion to the two FanGrids for air supply and exhaust air, the project scope included two control cabi­nets with MDC (MODBUS Display & Control) from Breuell & Hilgen­feldt. The MDC is a simple closed-loop system for control­ling the oper­ating para­me­ters. It also allows the optional inte­gra­tion of the oper­ating data into a building control system via a BUS system. This type of autonomous control has the addi­tional advan­tage that it is not neces­sary to inter­vene in the existing system’s often outdated control concept. “Stan­dard­ized cable outlets are used in the control cabinet,” explains Mayer. “However, the customer had thicker shielded cables because vari­able frequency drives were previ­ously in use. That was no problem for Breuell & Hilgen­feldt. They supplied the control cabi­nets with larger cable bush­ings.”

The customer was very satis­fied with the upgrade process. Thanks to the excel­lent collab­o­ra­tion between AIRnorm and Dieter Hilde­brandt at Breuell & Hilgen­feldt, the retrofit – including commis­sioning – was completed within three-and-a-half days. Subse­quent measure­ments have confirmed the antic­i­pated energy savings of 30 percent. “That’s around 54,000 kilo­watt hours per year. This is impres­sive and enabled the retrofit project to qualify for a subsidy from the Federal Office for Economic Affairs and Export Control (BAFA) – which was the icing on the cake,” summa­rizes Riedle with satis­fac­tion.