G/BA received an American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. (ASHRAE) Excellence in Engineering award for a chiller plant upgrade project at Advocate Illinois Masonic Medical Center (AIMMC).
G/BA was awarded this Excellence in Engineering Award at the ASHRAE Illinois Chapter, Awards Luncheon on December 12, 2014. Featured in the photo are G/BA staff and owner representatives who attended the awards luncheon. G/BA staff includes(back row, left to right), Dave Eldridge, Dennis LeBlanc, and Dan Doyle.AIMMC and the Advocate Health Care representatives (front row, left to right) include Darryl Dylla, Tom Baumstark, and Craig McKenzie.
AIMMC pursued this project to provide a more reliable cooling system, improve energy eficiency, reduce staff labor related to maintaining the chiller plant, and modernize the equipment in regards to refrigerant management in compliance with the Montreal Protocol. The project included replacement of the three main chillers serving the hospital, as well as new pumps and cooling towers. An additional air-cooled surgery chiller was replaced. Budget remained at the end of the project allowing for replacement of three additional air-cooled chillers, bringing all of the major chillers at the main hospital into compliance with the Montreal Protocol and significantly improving energy efficiency.
Three new high efficiency, 700 ton chillers with VFD’s and magnetic bearing compressors were installed. The design included the conversion of the cooling system to variable primary flow configuration from a primary/secondary arrangement. This reduced the project cost and saved space by eliminating half the existing CHW pumps. The design of the new cooling towers included the installation of new variable frequency drives. The full load design temperature difference was increased from 10° F to 12° F to further reduce flow and pumping energy usage. Four existing air-cooled chillers were replaced w/ new high efficiency chillers.
IMMC installed three very efficient magnetic bearing chillers to replace the existing machines. The new chillers are rated at a full load efficiency of 0.572 kW/ton and an NPLV of 0.339 kW/ton. The smaller air cooled chillers also qualified for ComEd incentives for exceeding IECC 2009 requirements.
Actual metered data shows the plant (including chillers, pumps, cooling towers) running at 0.672 kW/ton on a design day. During milder weather, the plant can be seen operating around 0.46 kW/ton.
The full load electric demand of the main chiller plant dropped by 200 kW (see attached graph), with the new air-cooled machines and primary only pumping configuration, this is further reduced. Whole facility electricity usage data indicated a large reduction during the 2013 cooling season, approximately 1,000,000 kWh for the period covering June, July, and August.