An average of around a million visitors come to the six-story Century Square Mall in Singapore every month for shopping, eating and entertainment. The shopping center opened in 1995 in the Tampines district, one of Singapore’s largest, about only ten minutes from the international airport. The mall’s operator, AsiaMalls Management Pte Ltd, determined in 2018 that the mall had become outdated and was having difficulty competing with its downtown rivals.
In addition, Singapore government had set new efficiency guidelines calling for a reduction in energy consumption and greening 80 percent of the country’s building stock by 2030. It was clear to management that the shopping center needed to be modernized.
The building management engaged an energy consultancy to explore solutions to improve energy efficiency in the building. One place where they found the energy consumption can be reduced was the Filmgarde Cineplex, a cinema on the fifth floor. It has six auditoriums in which up to 1,000 guests can enjoy Asia’s first AuroMax-3D-Sound, a technology featuring three layers of sound for an immersive spatial experience.
Unlike its advanced audio technology, the cinema’s air conditioning was not-state-of-the-art. Six units of AC belt-driven fans were installed on the building’s rooftop to cool the auditoriums. But the operating cost for these fans was high due to the frequent maintenance resulted from constant vibration. To solve these problems the energy consultancy called on ebm-papst. The two companies had cooperated on several projects previously.
Efficient and fail-safe
“The customer wanted to upgrade their AHUs to achieve better energy efficiency,” says Mark Ng, Sales Director at ebm-papst SEA Pte. Ltd. “So first we did some calculations on paper and ran a few simulations to make sure we could achieve the target.” Subsequently ebm-papst did a site study to determine the power consumption of the system on several days at different timings.
So far, six large AC fans have cooled the cinema in the Century Square Mall... (Photo: ebm-papst Southeast Asia)
... now 24 GreenTec EC fans in six modules take over this job. (Photo: ebm-papst Southeast Asia)
The solution soon became clear: “We proposed a FanGrid design consisting of four fans per AHU with a total number of 24 fans in six AHUs to replace the old AC belt-driven fans.” says Ng. The job was completed in only three days. With the retrofit, the AHUs at Century Square Mall are now operating on average 0.09 kW/RT which is only one fifth of Singapore Standard (SS553) for fan power limitation in mechanical ventilation systems (0.46Kw/RT).
Another additional benefit of the newly installed FanGrid is the built-in redundancy (N+1). “If one of the fans fails, the others can increase their output to compensate for it,” says Ng. “That rules out failures of the complete air conditioning system in the future. Moreover, the fans are maintenance-free.” The moviegoers also benefit; thanks to the quieter fans and lower vibration, they can hear even the quietest whispers in a film – and the 3D sound really comes into its own.