UHN had major representation at this year’s national CHES (Canadian Healthcare Engineering Society) conference, which was hosted in St. John’s Newfoundland (hence, the blog title). I was honoured to speak at the conference discussing some preliminary energy results of TGH’s new central cooling plant. I was lucky to share the stage with our former colleague, Chad Berndt, who was the mastermind behind the project. Chad is now working with the company that delivered the project, Enwave Energy Corp.



The presentation focused on the process of the project from initial data collection to approvals to design and construction to preliminary results. There was a heavy emphasis on data-based decision making as well as some of the key issues tackled by the new system, including:

  • Energy cost stabilization
  • Increased system capacity
  • Improved system reliability
  • Redundancy and resiliency of hospital cooling systems
  • Reduction in CO2 emissions
  • Simplification of building operation
Chiller Plant Renovation Project Process

You can read more about the technical information related to the project here. I would like to focus this blog on the huge energy and water savings that have been achieved. Check out the graphs below that show our utility consumption for our base case year, 2015, compared to data from summer 2018. On all three of the charts, you will notice a bump in May. There was an unusual heat wave very early in the year that required us to run chillers before the deep lake system was fully online. It is also important to point out that these charts are not weather corrected and, in fact, 2018 had 48% more cooling degree days compared to 2015. It follows that during a typical year, savings would be higher.

Electricity Peak Demand Savings:


Electricity Consumption Savings


Water Savings


These preliminary savings results suggest that the project is on the right track to outperforming the conservative estimates of $22M savings over the life of the project. I will post an update to the blog with final savings numbers upon the completion and approval of the final measurement and verification report.


What are people Saying?

The facilities operations team provided feedback on the project, including “the deep lake is rockin” and given the extreme heat, “the system really saved us this summer.” Even senior management took notice: