Louisville Medical Center Inc.

Chilled-Water System Optimization
Louisville, Ky.

Project cost 
$6.3 million
Time frame 

Feasibility study awarded – August 2006
Feasibility study completed – February 2007
Design awarded – April 2007
Design completed – September 2007
Contract award – November 2007
Construction completed – October 2008

Practice areas involved 
District cooling systems
Key services provided 
System optimization
Construction administration
Operations advice and training
The challenge 

In 1984, the Louisville Medical Center could not meet its cooling requirements with the existing chilled-water plant’s 13,000-ton installed capacity. A local consultant recommended installing additional chillers and cooling towers and expanding the building, at an  estimated cost of more than $5 million (1984). The Center called on Hemant Mehta, principal of WM Group, to provide a peer review of the recommendation.

The smart solution 

In 1984 as a result of the peer review and recommendations by WM Group’s principal, the system improved, delivering annual savings to the medical center’s energy budget. In lieu of adding more chillers, WM Group re-engineered the plant and converted the pumping system to a variable-volume primary pumping system. The implementation cost was $700,000 – substantially lower than the original $5 million estimate. The plant also regained 3,000 tons of capacity. Subsequent to the 1984 improvements, the center saved more than $400,000 in annual energy costs. Since 1984, Louisville Medical Center has relied on WM Group to perform all of its system upgrades and continue making dramatic improvements in capacity and energy savings. It continues to benefit from the innovative solutions, such as a two-speed chiller gear, common basin and a storage tank for condenser water.

The 2008 project designed the installation of a 5,500-ton chiller, a new cooling tower and a common condenser water sump for all the towers. The company oversaw construction and startup. Today, the plant’s capacity is 30,000 tons, achieved without expansion or encroaching on needed parking capacity. Its energy savings story is also dramatic: from an average cost of 17.4 cents/ton-hour in 1984 (35.2 cents in 2009 dollars) down to today’s 9.2 cents/ton-hour. And, the plant generates 71.92 million ton-hours/year compared to 15.4 million ton-hours/year in 1984.

“I recommend [WM Group] without reservation for any utility project you might have on your campus.”

Edward Dusch, General Manager