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
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.