I’se the B’y That Went to CHES

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:


UHN Cost Savings Analysizer

First off, congrats to the energy team Ed, Lisa, Songyang, Allan, and the recently departed Chad on saving almost $14M cumulatively since the start of the energy manager program at UHN! And now, some background information on how I came up with this number. It started with a question:

“If we are doing so much energy management, why are the bills still higher!?”

This question is a common one faced by many energy managers. There are numerous reasons why utility bills could continue to rise despite energy efficiency improvements, including rate escalation, weather variability, building expansions, space use changes, equipment degradation, and more.

The key answer to this question is actually another question – “How much would we be spending without energy management?” The new VP of our department, Ron Swail, challenged me to answer this question when he first came on board at UHN.

In order to do this, I built a weather regression model for each UHN site based on past weather and utility consumption data from before the first energy manager was hired at UHN. Weather regression correlates past weather with past energy consumption in a “baseline” formula to predict future energy consumption under different weather conditions (for example, during a hotter summer more electricity will be consumed for air conditioning). Thankfully, our fearless leader Ed Rubinstein has been keeping detailed utility and weather records for many years while he was developing the energy management program at UHN.

We also have records of past building expansions and renovations and estimations of their energy impacts. Where significant impacts occurred (ie large increase to building floor area), an adjustment is added to the baseline based on estimated/measured increase in energy consumption.

Now that we have a formula to calculate our expected energy consumption, we can apply the current utility rates to figure out what the cost would be. I conducted this analysis for each site and added them all up to come up with the following chart for all of UHN:

Cost Savings

Although actual costs (blue line) continued to rise until 2017, we can see that our “business as usual” cost (red line) was still significantly higher. The green area in between represents the costs savings with the green bar graph helping to visualize the same numbers. Did I mention that since UHN hired its first energy manager, we have saved almost 14 million dollars!!!!

To give you an idea of the cost escalation of utilities, I produced the same graph based only on actual energy consumption:

GJ Savings

To produce this graph I converted all of our energy consumption (kWh, m3 gas, ton-hours cooling, lbs steam) to a common unit of energy – the gigajoule (GJ). In 2013 and 2014, our expected energy consumption increased significantly due to addition of buildings (KDT) and weather effects. However, our actual consumption goes up much less than the baseline, meaning our energy efficiency projects are working and making our buildings more efficient. In 2016 and 2017 our expected consumption decreases, likely due to the cool summers requiring less electricity for air conditioning (I’m guessing this trend will reverse for 2018!). Note that in 2015 and 2016, our actual energy consumption went down while our costs went up!

This type of analysis is extremely useful for explaining the value of energy management to higher level and non-technical leaders in your organization. With a more accurate representation of just how much energy managers are contributing to cost savings, leaders can make more informed decisions on project priorities and budget allocations.

How did we achieve these savings? That’s a question for another blog here, here, here, here, here, here, here, and here.

New Chiller Plant Saves “Tons” of Energy at UHN’s Bickle Centre

With recent string of extremely high temperatures, it’s the perfect time to talk about how Bickle’s new chiller plant is saving us energy and improving reliability. For those less interested in the story and pictures, here are the cold, hard results: Continue reading

Mike at Home: The Sequel

When Ontario is giving out free smart thermostats, you know it’s time for a blog! Most of my recent blog posts have been about projects at UHN, so this time I’m going to change it up and talk about a couple of neat technologies I’m using at my apartment to save energy. Both of these savings ideas were mentioned in my previous Mike at Home Blog, but these new technologies really help to put those ideas into practice in a convenient way. There are many ways to save energy at home, even if you are a renter like me!

Smart Thermostat

I already had a programmable thermostat which was helping to save energy, but I wasn’t able to maximize savings for a couple of reasons. One way I typically try to save power is by setting back the thermostat if I’m away for a weekend or longer vacation, however this often led to an uncomfortably cold temperature for a few hours upon return. When energy savings lead to discomfort it can be difficult to maintain the energy savings behavior and I may have been less consistent in doing the temperature set back as a result. With my old thermostat on the fritz, I took the opportunity to upgrade to a web-connected thermostat.


New Thermostat (source)

Continue reading

You down with DCV at KDT? Yeah you know me!

Whether you want to send a car to space or implement an energy project, you must measure and track results! One of the biggest things we do here at the Energy and Environment team is to measure and track project results because it gives us real world information that we can use to accurately evaluate similar projects in the future. This post is about the recently completed demand controlled ventilation (DCV) project at the Krembil Discovery Tower (KDT). This project follows in the footsteps of similar projects that we worked on with UHN Research at the Princess Margaret Cancer Research Tower (PMCRT). Since we had such good proof of concept results from PMCRT, it made for a much easier decision to proceed with the project at KDT. Let’s take a look at the project and results!

Here’s a preview of the savings for those that don’t have time for all the details:

  • Electricity Demand Savings: 310.6 kW (equivalent to about 630 window AC units)
  • Electricity Consumption Savings: 1,433,353 kWh (equivalent to 161 typical Canadian houses annual consumption)
  • Natural Gas Savings: 418,343 cubic meters (794 tons of CO2, equivalent to taking 169 cars off the road)
  • Utility Cost Savings: $241,337

Krembil Discovery Tower (Image Source)


Continue reading

The Sixth Sensor – I See Live People!

Looks like I might be starting a trend referencing old 90’s movies on the Talkin’ Trash blog. This time, with Halloween fast approaching, we are taking a spookier turn as we look at the recent stairwell lighting project at TRI University Centre.

6th sense quote

If you want to hear something really scary, Continue reading

Bike Like Mike

There is no better time of year than now to ride your bike to work (or to the gym, or to the grocery store, or just for fun)! Fresh crisp air and cool morning temperatures help to ensure you won’t end up a sweaty mess on arrival. Biking regularly can help you get in shape, feel better, improve your health, and it’s just plain fun! Check out this TED Talk about the awesome ways that biking can change you.


I’ve been meaning to write a blog on biking ever since the large expansion of Toronto’s Bike Share system this summer. Continue reading