© Photo | ebm-papst

Upgrade to the power of three

EC instead of AC, a new fan type and econom­ical cold aisles — when upgrading its server air-condi­tioning system, the Danish company William Demant didn’t do things halfway.

Generous offices, tasteful furnish­ings and lots of light: When the Danish hearing-aid manu­fac­turer William Demant moved into its new head­quar­ters, they offered every­thing the heart desires for a modern office. Only the cooling air-condi­tioning system in the server room couldn’t quite keep up. Large belt-driven fans ran in the air-condi­tioning units and used a great deal of energy.

That didn’t fit into the company’s concept, which places great impor­tance on envi­ron­mental protec­tion and energy effi­ciency. As a result, those respon­sible looked around for alter­na­tives. On the subject of air condi­tioning, Henrik Jensen, Service Manager at William Demant, imme­di­ately thought of ebm-papst: “I was already familiar with the prod­ucts from my previous job and I knew what kind of perfor­mance they can deliver.”

Support for a neighbor

It didn’t take long for Henrik Dahl Thomsen, Product Manager at ebm-papst, to get to the first appoint­ment for a visit to William Demant. His office is in the imme­diate vicinity of the hearing-aid manu­fac­turer. In the server room Thomsen first obtained an overview of the cooling system’s condi­tion. As is usual in rooms of this kind, the air-condi­tioning units route the warm air out of the server room, cool it down and then blow it into a subfloor. From there the cooled air flows through small open­ings in the floor and cools the server located in the room.

“However, at William Demant we imme­di­ately noticed a special design feature. The AC fans were curved forward and installed quite a bit above the floor and pressed the air down­ward from there. This had the disad­van­tage that they actu­ally blew the air directly onto the floor, which then deflected the air flow by 90 degrees. That slowed down the flow of air and made the system even more inef­fi­cient.” Together with his part­ners at William Demant, Thomsen looked for a more effi­cient possi­bility and proposed that the fans were not only be replaced, but that their posi­tion in the air-condi­tioning unit would also be changed. As a result, they were no longer to be installed directly in the unit, but instead recessed in the floor. More­over, Thomsen proposed a back­wards curved fan, which routes the air hori­zon­tally under the floor directly towards the server.

Simple conver­sion

“Even though I had never seen this type of instal­la­tion before, the proposal imme­di­ately sounded plau­sible,” remem­bers Henrik Jensen. “So we ordered the modi­fi­ca­tions and a tech­ni­cian installed RadiPac EC fans.” Only minor work was required for this conver­sion. The instal­la­tion tech­ni­cian enlarged the hole in the floor of the cooling units, enabling the fans to be recessed in the floor. As the compact fans are supplied as a complete module with a frame, they then only had to be screwed into the opening in the floor.

At the same time, William Demant imple­mented an addi­tional measure that makes the computer center even more effi­cient: The company intro­duced a so-called cold aisle. For this purpose, it installed enclo­sures around every second corridor in the server room. This enables the cold and hot air to be sepa­rated more effec­tively and the entire system can be oper­ated with less energy due to this clear sepa­ra­tion.

This restruc­turing in the cooling room brought William Demant energy savings of 23 percent, and the conver­sion to EC fans reduced the energy consump­tion by another 38 percent. Through the decreased elec­trical costs, the invest­ment already paid off for the hearing-aid manu­fac­turer after about one year. In addi­tion, the modi­fi­ca­tions enable the temper­a­ture around the server to easily be kept below 27 degrees centi­grade (81 degrees Fahren­heit). That’s impor­tant, as the servers’ own small fans are not started until this temper­a­ture limit is exceeded. If they remain inac­tive, addi­tional energy is saved.

Thanks to their low noise level, the RadiPac EC fans also make it easier for the tech­ni­cians to work in the server room, as they can now work with fewer distur­bances. Henrik Jensen is extremely satis­fied with the upgrade: “The energy savings were even greater than we had hoped. You don’t see that every day.”


Discover more:

ebm-papst in data centres

Cool solu­tions for hot tech­nology.

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