G/BA provided engineering design services for the replacement of the main cooling plant and four departmental cooling units in this 1.14 million-square-foot hospital. The construction cost was $5.5 million.
|2014 Regional Technology Award, ASHRAE Region VI (first place)|
|2013 Excellence in Engineering Award, ASHRAE Illinois Chapter|
Three new high-efficiency, 700- ton chillers with variable frequency drives (VFDs) 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 and the installation of all new premium-efficiency motors. New cooling towers with VFDs resulted in a temperature difference design change from 10°F to 12°F to reduce flow and pumping energy usage.
Four existing air-cooled chillers were replaced with new high-efficiency chillers, including:
The new air-cooled chillers are designed with higher efficiency pumping systems. All chillers were selected using life cycle cost analysis to minimize total cost of ownership over the next 30 years. The refrigerant does not have ozone-depletion potential.
The main chiller plant now has N+1 redundancy, improving serviceability and reliability of the plant as a whole. Three main chilled water pumps were installed on a header, allowing any one pump to be out of service at any time. Condenser water pumps are also on a common header.
G/BA helped Advocate obtain ComEd rebates as a result of the new energy efficient design, including:
The project resulted in estimated energy savings of over $100,000 per year. The total operating efficiency of the new plant is between 0.42 - 0.56 kW/ton, including pumps and cooling towers.