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)


KDT is a world class research centre with a wide array of ground breaking research being conducted in various fields of neuroscience. The 9-storey building has 5 full floors of dedicated research space supporting more than 150 neuroscience specialists in their research.

Unfortunately for our utility bills, laboratory spaces are well known to be energy hogs. Designers often design lab spaces based on the worst case scenario of a chemical spill in the space. On these rare occasions, air needs to be circulated rapidly in order to clear any hazardous substances from the air. To cover these conditions, designers typically specify a very high air change rate up to 10-12 air changes per hour. This means the entire air volume of the space is being changed over every 5 minutes! All that air needs to be heated and cooled, leading to astronomical utility costs.

KDT was designed with many energy efficient features and, in fact achieved LEED Silver Certification, but due to difficulties encountered during commissioning many of the features were not functioning optimally. Here is a point form run down of some of the difficulties encountered:

  • Office spaces adjacent to the lab spaces were designed for variable air volume to save energy
  • However, due to the high air change rate in the labs, the air balancer was unable to balance the building pressurization when the office air handling units (AHUs) ramped down to lower flows
  • As a result, the office areas had to be operated at full flow all the time in order to maintain adequate relative space pressurization and separation of air flows
  • With all AHUs running full out 24/7 the building’s energy performance was not as good as it could be

DCV Project

This brings us to the Demand Controlled Ventilation (DCV) retrofit project, which has helped to solve all of these issues. Similarly to the DCV project at PMCRT, UHN worked with Airgenuity to install air quality sensor technology throughout the laboratory spaces. Sensors were installed in mechanical spaces for easy maintenance, with air sampling connections extending to each space. The sensor suite cycles through all the spaces, sampling the air and testing for any contaminants. Each space is tested a minimum of once every 10 minutes. Information from the sensor suites is fed to KDT’s building automation system, giving us a real-time space by space snapshot of the air quality throughout all of the labs in the building.


Example of a sensor suite with vacuum pumps to draw air from the lab spaces

With this key information related to air quality available, we no longer have to circulate air as if a chemical spill is continuously occurring. New control strategies have been put in place to provide 3 air changes per hour during high occupancy business hours and 2 air changes at night during low occupancy hours. These are typical air change rates for comfort and safety in a working environment. Whenever an air quality contamination is detected, the related AHU ramps up to full purge mode of 12 air changes per hour until the air is proved to be clean. Considering spills happen very rarely, the savings from this new operation have been fantastic.

Another key benefit of this project is that it helped to alleviate the commissioning problems listed in the background section above. With the laboratories operating at a lower air change rate, it became possible to do proper air balancing of the office side of the building. All of the local controls in the office spaces were enabled to allow the variable flow system to operate as intended, leading to even greater savings.

The fume hood exhaust system was also included as part of this retrofit. This portion of the project is very similar to the exhaust fan retrofit at PMCRT, so I will refer you to my previous blog post for more info on that aspect of the project.

Energy Savings

Now, to the good stuff! As mentioned at the beginning of this post, the energy and environment team is all about monitoring and verifying savings so that we know if the project actually did what we thought. In this project, we installed multiple submeters on AHUs and central plant cooling equipment. We monitored all of these for at least 10 months both before and after the project to generate baseline consumption numbers and post retrofit numbers. The electricity savings were so large that they actually showed up on the main building electric meter showing that we saved 10% of the electricity used in the entire building! Huge gas savings were also achieved because the lower air volumes mean we are doing much less air heating.

Electricity Trend

Post-Retrofit energy consumption consistently lower than baseline

Now for the numbers:

Without the support of incentive programs from Toronto Hydro/IESO and Enbridge this project wouldn’t have been possible. These programs contributed over $300,000 to the funding of the project and shows the strong commitment both organizations have towards energy efficiency and greenhouse gas reductions. Special thanks to Jana Jedlovska of Toronto Hydro and Matt Cannon of Enbridge for their support with the applications.

Thanks also to Airgenuity for the design/implementation of the project, as well as Ian McDermott’s UHN Research project management team and Rick Ysidron’s facilities team for all their hard work and support during the project. We are collaborating on many new energy savings projects every day!

So I’ll ask again, who’s down with DCV at KDT!? Every last laboratory!

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