Water heater that cools rooms, dries clothes

Seven undergraduates and three PhD students will receive grants from NUS Enterprise to develop creative ideas into prototypes, start-ups or commercially viable products. Lester Kok looks at two of these projects.
Straits Times 13 Mar 10;

HOW would you like a two-in-one machine that heats up your water as well as cools your rooms with cold air?

This is the proposed prototype that two students from the National University of Singapore (NUS) came up with based on existing research done by their professors.

If they succeed, commercial businesses as well as households could slash their water-heating electricity bills by almost 75 per cent.

The duo, who call their group Soleil Water, are now using a grant from NUS to build a scaled-down version of their commercial prototype, a three-in-one system that heats water up to 60 deg C, cools a room down to 20 deg C, and dries 1.5kg of wet clothes in less than an hour.

The whole system, invented by Dr M.N.A. Hawlader from NUS' department of mechanical engineering and his PhD student Mohd Amin Zakaria, works on the idea of heat transfer where heat is extracted from the surroundings and used to heat up water.

Co-founder Darrell Zhang said the group hoped its project would use energy efficiently and reduce the carbon footprint.

'We feel that heating up water is a waste of electricity, when it can be better used for other devices,' said the 25-year-old engineering student.

'That is why we came up with an efficient way to utilise waste heat from air-conditioners and ambient heat from the air. In this way, we are using electricity as an engine to draw upon renewable and recyclable sources of energy.'

His partner, business student Bryan Lee, cites the example of a four-star hotel with almost full occupancy requiring about 150,000 litres of hot water daily.

The operating cost of producing hot water using a fuel boiler is estimated at $2.23 per 1,000 litres of water.

'With our system in place, we can potentially reduce the operating costs to less than $1 for every 1,000 litres,' the 27-year-old said.

For now, the domestic model has yet to make it to the drawing board, but the commercial prototype will be installed in a nursing home for a pilot test.