UNIVERSITY CENTER, Mich. (AP) — Twenty miles of tubing running through water retention ponds will help supply heating and cooling to Saginaw Valley State University's new Health and Human Services Building.

The school says the cost-saving system will transfer heat from the building to the water in the summer and draw heat from the water to warm the building in the winter.

Spokesman J.J. Boehm says the aqua-thermal portion of the heating and cooling system cost about $319,000.

But he says the interior equipment is costing $187,000 less than with a conventional climate control system.

Boehm says the university will save about $71,000 a year and pay for the system in less than two years.

The $28 million building opens in August 2010.