The demand for cooling in Singapore’s buildings

According to the Energy Market Authority, the building sector accounted for 37% of all of Singapore’s electricity consumption in 2014.  Under the Building Control Amendment Act of 2012, building owners are required to submit energy consumption data to the Building and Construction Authority (BCA) on an annual basis.   In 2014 the Building and Construction Authority released their first benchmarking report, looking into the energy trends within 884 commercial buildings.  This report has been updated in 2015, and they now have access to data from over 1,000 commercial buildings, equating to over 20million m2.

They have started tracking the breakdown of building type, gross floor area, energy intensity and energy utilisation year on year.  Nearly 50% of all commercial buildings are offices, with hotels and retail buildings making up the majority of the rest of the buildings.

Sitting just over one degree above the equator means that Singapore is hot, all year round.  The scale and extent of the buildings, and the level of air-conditioning that you feel whenever you walk into one makes you realise that the energy being used to cool buildings down is no small statistic.  The BCA reports that air cooling in non-residential buildings account for 60% of all electricity consumption, with a further 10% used on mechanical ventilation.  In the 2015 benchmark report, they indicate that 77% of all large commercial buildings are cooled by centralised chilled water systems.  It is no surprise then that so much of the emphasis at the International Green Building Conference last week was on energy efficiency retrofits in commercial buildings, and that the majority of discussion on suitable interventions focused on improving the efficiency of the cooling system.

Michael Anderton of Johnson’s Controls spoke on a retrofit project that he’d been involved in, addressing inefficiencies in the Lucky Plaza mixed use building on Orchard Road.  They engaged with the building owners on a guaranteed savings ESCO model, and through the redesign and retrofit of the building’s cooling system, they have been able to save nearly S$1million every year on energy costs.  Some of the main areas that they addressed were:

• inefficient piping layout, with too many bends and corners;
• over-spec’d pumps; and
• badly maintained cooling towers.

The sizing of the pumps seems to be quite a big issue here, as Lee Eng Lock from Monitoring & Verification put it – the cooling systems in Singapore are effectively like a person washing their hands with a fire hose.  The BCA has a target for 80% of all buildings to be Green Mark rated by 2030; the redesign of air conditioning and cooling systems will be very important in the achievement of this target, and it should have a marked impact on the energy intensity of Singapore’s building stock.