Cool way to fight global warming

Jalelah Abu Baker, Straits Times 26 May 09;

TAKING the fight against global warming to new heights, five students here want to start irrigating Singapore's rooftops.

After almost eight months of research and experimenting, five students from St Andrew's Junior College have identified water as the perfect means to cool buildings, reducing the need for air-conditioning.

They found that water absorbs the sun's heat and effectively blocks it from entering buildings, thereby providing a comfortable temperature in the rooms below.

To prove this, the students devised a model with a wide layer of water on its roof, all enclosed within a transparent or metal case.

Their experiment has taken them to the final round of the National Weather Study Project Competition, which challenges students from all levels to come up with ways to save the environment.

But their water-roof model did not find favour in the earlier rounds of the competition. As group member Donovan Foo, 17, put it: 'The judges tore our project apart.'

The group had initially suggested using rainwater, which was dismissed as impractical. They also suggested that the roof could double as a water soccer arena, which came with its pitfalls.

Other entries in the competition sought to tackle global warming using a more academic approach.

Students from Nanyang Girls' High School want schools to switch off air-conditioning at specific times of the day to help optimise students' studies.

The girls discovered, after plotting Singapore's weather patterns, that the best temperature range for students to memorise facts and figures is between 25.9 deg C and 27.3 deg C.

The island's temperature stays within this range from 7am to 10am.

They administered a visual and textual memory test six times to the same 30 students at different temperatures to derive these findings.

Both schools used a weather console sponsored by Senoko to carry out their experiments.

Senoko, Singapore's largest power generation company, in collaboration with the National Environment Agency and other private companies, has been organising the competition since 2006.

The finals tomorrow will see 14 schools competing in the primary, secondary and tertiary levels, with prizes of up to $10,000 to be won.