© Inge Bang

New venti­lation system has half the appetite

After replacing 283 elec­tricity-gobbling AC fans with effi­cient RadiPac EC fans from ebm-papst, the elec­tricity costs for the resi­dents of a Danish resi­den­tial complex imme­di­ately dropped by 50 percent.

Torben Lintrup Kirk­holt had to be more persua­sive than usual in Farum, Denmark. And not only with the engi­neers who are respon­sible for awarding contracts. For this job, the managing director of ebm-papst Denmark even had to nego­tiate directly with the repre­sen­ta­tives of the “Farum Midt­punkt” resi­den­tial complex owners’ meeting. The project on the table was not a small one: the building complex’s venti­lation system was terribly outdated. The 283 old, elec­tricity-gobbling AC fans from the 1970s needed to be replaced by new, energy-saving RadiPac EC modules. Kirkholt’s greatest obstacle: the planned reno­va­tion concept first had to be passed by a majority of the 4,100 resi­dents. And the costs made them skep­tical: the total cost of reno­va­tion was at € 2.7 million. “We were certain that we would deliver the energy savings we promised the resi­dents, which meant that the system would quickly pay for itself,” said Kirk­holt. This is why he employed unusual means: “We signed a contract guar­an­teeing the savings. If we did not achieve them as promised, we would have to refund the differ­ence. This convinced the commu­nity of owners.”


Replacing elec­tricity-gobbling AC fans with effi­cient EC fans reduces energy costs by half – for the resi­dents of Farum Midt­punkt this plan worked out. (Photo | Inge Bang)

Calcu­lated for the long term

The high level of energy savings was the deciding factor in the process from the very begin­ning. “Of course we wanted a solu­tion that focused on facil­i­tating improved venti­lation for the apart­ments,” said Alex Rytt, senior consul­tant at KAB, the manage­ment company respon­sible for the complex. “But we didn’t have to settle for the cheapest alter­na­tive. We were inter­ested in both modern­iza­tion and a reduc­tion in energy consump­tion.”

That is why YIT Denmark received the contract. After all, the company empha­sized energy savings in its reno­va­tion proposal by including EC fans from ebm-papst. And the parties involved in the project were convinced that the fans would also require lower main­te­nance and emit less noise. The crew got to work. Over a 2-month period, they replaced the 283 AC fans on the resi­den­tial complex’s roof with 283 RadiPac EC fans, cleaned all the venti­lation shafts and replaced the exhaust hood in each home.


Over a 2-month period the instal­la­tion team replaced the 283 AC fans…


…with effi­cient RadiPac EC fans. (Photos | Inge Bang)


Energy consump­tion cut in half

The parties respon­sible deter­mined the results of the modern­iza­tion over the period of a week. They recorded the consump­tion data before and after the conver­sion directly on the old and new devices. The results were impres­sive: the measure­ments showed a savings of 52 percent. “The results exceeded our wildest expec­ta­tions,” said Rytt enthu­si­as­ti­cally. The resi­dents of the Farum Midt­punkt complex also had a reason to be happy, because the effi­cient fans cut their annual energy costs in half: from more than €134,000 to around €68,000. This means the new fans systems will already have amor­tized them­selves in approx­i­mately 10 years. For Torben Lintrup Kirk­holt, the result is also proof that it pays to stray from the well-trodden path some­times: “Above all, the direct contact to the end users was the key to this project.”

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