When the skyline in Hong Kong is brightly lit at night, viewers’ eyes also light up. Hong Kong Elec­tric plays a role in making the night­time city sparkle. After all, the company supplies more than 570,000 private house­holds and commer­cial customers in Hong Kong with elec­tricity. Until now, the energy supplier has also needed quite a bit itself — for the air condi­tioning system in its building on Ap Lei Chau, an island located to the south of Hong Kong. The system was no longer state of the art. It gobbled up power and after 10 years in oper­a­tion, the AC fans it used often required main­te­nance. That is why Hong Kong Elec­tric started searching for fans that work reli­ably, fit into the existing venti­lation system and save energy. The company turned to ebm-papst Hong Kong. And Hong Kong promptly asked the colleagues in Sweden for their support. Daniel Yiu, Regional Sales Manager in Hong Kong, explained that: “ebm-papst Sweden is our expert for retro­fits. Since the early 1990s, our Swedish colleagues have retro­fitted existing venti­lation systems according to customer require­ments.”

Strict fire safety regu­la­tions

The energy supplier Hong Kong Elec­tric switched to energy-saving axial fans. Daniel Yiu from ebm-papst turned to his colleagues in Sweden for support. (Photo | ebm-papst)

Together, the teams quickly found the ideal product: MXAC compact EC centrifugal fans fulfilled all the require­ments. But for use in the building, they had to fulfill a partic­u­larly high fire-resis­tance class. “Hong Kong has detailed regu­la­tions on the temper­a­tures the sealing mate­rial and sealing points must with­stand and they are different from those of other coun­tries,” said Björn Jonsson, Marketing Manager at ebm-papst Sweden. “In order to meet the strict fire-protec­tion regu­la­tions, we had to adjust the seals and damping of the fan frame and we mounted adjustable profiles with spring shock absorbers.” After doing so, they deliv­ered the “Hong Kong version” of the MXAC for a test.

Hong Kong Elec­tric had three venti­lation devices that were primarily respon­sible for supplying the office spaces in Ap Lei Chau with fresh air. The replace­ment took only five hours per unit. The measured values were inspiring: at the same air flow and static pres­sure output, the EC fans consumed 50 percent less energy than their prede­ces­sors. Instead of 6.75 kW, a fan only required 3.4 kW per hour. The savings in oper­a­tion are derived from the vari­able fan speed control. And thanks to their direct drive and compact construc­tion, the fans require virtu­ally no main­te­nance. The energy supplier was convinced: it grad­u­ally replaced fans in the entire building, a retrofit in further build­ings is to follow.

ebm-papst Sweden deliv­ered a total of 30 fans for the entire Hong Kong Elec­tric Tower in Ap Lei Chau. With them, the energy supplier can save 270,000 kWh of elec­tricity per year.