St. Franziskus-Stiftung Münster, a foun­da­tion that is one of the largest denom­i­na­tional hospital groups in Germany, has 18 hospi­tals and ten facil­i­ties for the disabled and elderly. Running this many facil­i­ties entails a huge amount of energy consump­tion at a time when cost pres­sure is increasing throughout the industry. The air handling units (AHUs) in several of the Foundation’s hospi­tals are over 20 years old in some cases and can no longer adequately venti­late newer exten­sions due to their limited capacity. “So it was time to modernize the outdated fans in the venti­lation systems along with the control cabi­nets and control tech­nology, for which there are no longer any spare parts,” explains Verena Gölkel, press spokes­woman for the Foun­da­tion.

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.

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

To plan and imple­ment the modern­iza­tion, the Foun­da­tion turned to FACT GmbH, a subsidiary providing tech­nical services in the health­care sector. As part of St. Franziskus-Stiftung Münster, FACT was founded around 25 years ago as a provider of services such as consulting, tech­nical building services plan­ning, construc­tion and project manage­ment, hospital tech­nology, hospital IT, medical tech­nology, busi­ness services and medical docu­men­ta­tion for the entire Foun­da­tion. 

(Photo | ebm-papst, Frank Peterschroeder/Fotogloria)

Markus Prinz and Markus Prior, Building Automa­tion Divi­sion Managers at FACT GmbH, were respon­sible for plan­ning and imple­menting the retrofit. “Once the deci­sion to carry out retrofit had been made, we looked around the market for EC fans and came across ebm-papst,” explains Prinz. The conver­sion from outdated, belt-driven AC fans – such as those still found in most of the Foundation’s hospi­tals – to modern, energy-effi­cient EC fans offers substan­tial poten­tial for savings. “Along­side other suppliers, we were partic­u­larly impressed by the quality, perfor­mance and energy effi­ciency of ebm-papst’s fans and motors,” adds Prior. So FACT reached out to ebm-papst sales partner Breuell & Hilgen­feldt, who handled the fan design and supplied suit­able fans from the RadiPac and RadiFit series for the retrofit.

Saving energy while patients sleep

In addi­tion to the issues of sustain­ability, energy and cost savings, there was another reason for the retrofit: a new set of guide­lines from the Asso­ci­a­tion of German Engi­neers (VDI). Since DIN 1946-4 was last updated in 2018, hospi­tals have been able to partially or completely switch off their venti­lation systems for certain OR areas at night – some­thing that was previ­ously not permitted. “Many hospi­tals don’t even know that these new guide­lines exist, even though they can save a lot of energy costs,” says Markus Prinz. 

The distinc­tion in DIN 1946-4 between two classes of rooms is crucial here: Class I rooms include oper­ating rooms. Here, AHUs may be switched off if the systems continue to operate for at least 30 minutes after the rooms have been cleaned for the last time and all the doors have been closed, so that any mois­ture intro­duced during cleaning is completely removed. Class II rooms include exam­i­na­tion rooms, emer­gency admis­sion rooms, inten­sive care rooms, recovery rooms and delivery rooms. In these rooms, the AHUs can be switched off completely.

The night-time shut­down is controlled via FACT-designed control panels on the OR equip­ment that allow the venti­lation systems to be oper­ated easily and effi­ciently. An intu­itive user inter­face makes it easier for medical and cleaning staff to switch the systems on and off as required, which also helps to save energy. The retrofit and the new intel­li­gent fans enable the system to be controlled by panel as well as through the building manage­ment system. The fans provide the neces­sary data via MODBUS, are oper­ated as required and make night-time shut­down and the resulting savings easy.

Demand-based control with sensors

Another compo­nent of the retrofit was the instal­la­tion of sensors to measure things like the temper­a­ture, humidity, and CO₂ content of ambient air both in oper­ating rooms and in meeting rooms, seminar rooms and other inte­rior rooms. Room occu­pancy and other para­me­ters are also recorded and moni­tored in FACT’s building manage­ment system. This is partic­u­larly impor­tant in hospi­tals, where AHUs often have to meet specific and constantly changing room and air flow require­ments. Combined with energy-saving EC fans from ebm-papst, these sensors enable precise, demand-based control. This is because the EC fans can be precisely regu­lated across their entire speed range and even work more effi­ciently at low speed in the partial load range. This allows the system to deliver the exact amount of air required at all times, ensuring optimum indoor air quality while maxi­mizing energy effi­ciency.

Quick instal­la­tion thanks to plug & play

In hospi­tals, the avail­ability and reli­a­bility of AHUs are essen­tial. For this reason, and espe­cially for systems respon­sible for oper­ating rooms, time windows for conver­sions are extremely narrow, often limited to one or two days, usually falling on week­ends or at night. These narrow time frames require compo­nents that enable quick and effi­cient imple­men­ta­tion – such as the RadiPac and RadiFit fans, which are plug & play and can there­fore be installed and put into oper­a­tion in a very short time. FACT has also devel­oped special shaped connec­tors for its own purposes, which make it even easier to install the fans.

RadiPac 2

RadiFit

In the five hospi­tals, the new, energy-effi­cient RadiPac and RadiFit fans from ebm-papst are already providing optimum venti­lation and ensuring a reli­able working envi­ron­ment. (Photos | ebm-papst)

Climate neutrality and cost pres­sure

Sustain­ability is a key compo­nent of St. Franziskus-Stiftung Münster’s corpo­rate strategy. Switching to a more CO₂-friendly anes­thetic and reducing pack­aging and hospital waste are just some of the measures, says Verena Gölkel: “Venti­lation systems account for around 30 percent of elec­tricity costs in the hospi­tals. This gives us the oppor­tu­nity to achieve substan­tial savings. We imme­di­ately recog­nized the poten­tial of retro­fits as a way of reducing current consump­tion.”

We have set ourselves the goal of grad­u­ally moving all 18 of the hospi­tals we run toward climate neutrality. Retro­fitting is essen­tial for this.

Verena Gölkel, press spokes­woman for St. Franziskus-Stiftung Münster

Impres­sive savings

For these reasons, the deci­sion was taken to use EC centrifugal fans from the RadiFit and RadiPac product ranges. Under the lead­er­ship of Markus Prinz and Markus Prior, the FACT team replaced a total of 70 old fans with modern, energy-saving EC models in 18 AHUs across five hospi­tals.

Thanks to these measures, the Foun­da­tion was able to achieve signif­i­cant energy savings of 110 kWh per hour, which equates to an annual saving of 920,676 kWh. Assuming an elec­tricity price of €0.30/kWh, this results in annual cost savings of over €275,000. Another major contri­bu­tion to energy savings can be made by switching off the OR systems at night. This increases energy savings by roughly another 30 percent.

In the five hospi­tals, the new, energy-effi­cient fans from ebm-papst already ensure optimum venti­lation and guar­antee a reli­able working envi­ron­ment. The modern­ized AHUs not only contribute to consid­er­able energy savings, but also improve the ambient climate for patients and staff thanks to sensors and moni­toring. These results have impressed the Foun­da­tion, and it is now plan­ning to convert the other facil­i­ties to EC fans as well.