Cool savings with new air-con system

Grace Chua The Straits Times AsiaOne 23 Aug 14'

A cheaper, more efficient air-conditioning system to run a 50-storey office building has been developed by a team of Swiss and Singaporean researchers.

The system, which could save 40 per cent in energy costs, will be used for the first time in Asia at an international school in Singapore.

Not only does it reduce energy costs, it also takes up less space than conventional means, translating to construction cost savings of up to 29 per cent.

The developer of the energy-efficient building technology, Future Cities Laboratory, signed a deal yesterday to install it as a prototype at a $50 million addition being built at the United World College of South East Asia's Dover campus.

The 24,000 sq m school building will be completed by next year and, in 2018, Future Cities Laboratory hopes to showcase the system's performance to potential buyers such as commercial property developers.

The potential savings are significant as, in Singapore, consumption by buildings makes up nearly a third of total electricity usage, and 60 per cent of buildings' electricity use goes to cooling.

Conventional air-conditioning systems use water at 6 deg C to dehumidify and cool air, which is then piped around a whole building through air ducts.

The prototype, however, dehumidifies air first using small ventilation units built directly into the building's facade. This cuts the amount of ductwork required for transporting the air.

It also uses a separate cooling system: Chilled water - which needs to be only 17 deg C - is injected into special ceiling beams to cool the surrounding area.

As water can absorb more heat than the same volume of air, using these ceiling beams to cool a room takes up much less space than conventional overhead air ducts.

The technology is already used in Swiss offices for heating, but was adapted for cooling in the warm, humid tropics.

Future Cities Laboratory is set up under a National Research Foundation programme called Create (Campus for Research Excellence and Technological Enterprise), in which Singapore collaborates with different foreign universities.

UWCSEA head of college Chris Edwards said of the decision to use the new system: "We do have pragmatic motives. Sixty per cent of our energy bill goes to air-conditioning, so we are genuinely thrilled about the prospects."