Replacement of Water Cooled System


There were two outdated cooling towers on the roof as well as five 18-year old R22 chillers in the basement of the building that had served beyond their useful life and needed to be replaced. Donnelly’s design build approach determined that replacing the existing water-cooled system with an air-cooled chiller system was the best solution – allowing for less equipment, more efficiency and better serviceability. Additionally, as The Town Hall is a national historic landmark, special steps needed to be taken during the planning and construction phases to meet codes and regulatory requirements.


  • Design a new, more efficient system
  • Disconnect, remove and dispose of (5) old chillers in the basement and (2) existing cooling towers from roof
  • Provide and install new steel dunnage on the roof to handle new equipment with new isolation springs
  • Set new 110-ton air-cooled chiller on the roof by use of crane
  • Install ultra-quiet sound insulation package with the new chiller to minimize noise levels
  • Provide and install scaffolding up the side of the building for the removal of the old piping and installation of new steel chilled water piping
  • Run new chilled water lines and power up the side of the building
  • Connect existing piping to the new chiller and existing connection in mechanical room
  • Provide chemical flush of piping and test
  • Install weatherproofing insulation on all new piping
  • Connect new electrical feed to chiller
  • Provide all required drawings and permits for the job, including landmark status
  • Start and test the newly installed system


From Donnelly Mechanical leveraged its design build expertise to provide a new design and an enhanced air-cooled solution that:

  • Eliminated all chemical treatment and testing, and associated costs, required for cooling towers;
  • Saved valuable space in the basement needed by The Town Hall;
  • Generated considerable savings on electricity, with ROI achieved in less than 3 years.

Donnelly was involved in every phase of the project: from design right through starting and testing the newly installed system, including supplying the drawings and executing all aspects of the turn-key installation. This afforded The Town Hall management a single point of contact throughout the entire process for a smooth and successful project.

“I wish to thank Donnelly Mechanical for the installation of our brand-new air conditioning equipment. Throughout the entire six-month process, their Project Manager was always available to us. He was responsive to every concern and took special care knowing the hall is a national landmark. When an issue would surface, he was there to work through it with us. We highly recommend Donnelly for their quality service and their team.”

Executive Director, The Town Hall Foundation 

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