Measure in Order to Manage
It’s fair to say that when it comes to progressive energy efficiency initiatives, the province the British Columbia often leads the way in Canada. In January, some municipalities in the Greater Vancouver Area (Burnaby, Surrey and Vancouver) became engaged in a new voluntary pilot project designed to encourage local building owners and managers to benchmark the energy use and emissions of their properties and get involved in a disclosure program.
The voluntary program echoes the Canada Green Building Council (CaGBC) Disclosure Challenge initiative announced last year (and mentioned in the last issue of Energy Manager Canada ), where five major property management organizations (QuadReal Property Group, Triovest Realty Advisors, Concert Properties, Colliers International and the Minto Group) have volunteered to participate.
Both programs are collecting data based on the ENERGY STAR Portfolio Manager interactive energy management tool to provide energy managers relevant information to perform their jobs better.
These voluntary benchmarking programs are positive steps in getting building owners to
“Voluntary benchmarking programs are positive steps in getting building owners to recognize that by measuring and comparing their energy use with similar properties in similar geographies that they can identify areas within thier portfolios that need improvement.”
recognize that by measuring and comparing their energy use with similar properties in similar geographies that they can identify areas within their portfolios that need improvement.
Getting municipalities and utilities involved in these programs can also aid in helping develop incentive programs for where building owners need them most.
The province of Ontario has actually legislated the reporting of energy use by buildings—at least those 100,000 sq. ft. or larger.
Ontario’s Energy and Water Reporting and Benchmarking (EWRB) initiative was first announced in 2016 and was made law in 2018. The regulation has been gradually phased in, beginning with the largest building sizes. Buildings of 50,000 sq. ft. up to 100,000 were slated to begin reporting data this year (based on 2019 results), but the current provincial government has placed a hold on that legislation, making the reporting for this segment of the market voluntary.
For now the province is collecting data for buildings and in the future will publish the building performance data to the public allowing property owners/managers to compare their usage to similar buildings.
This type of reporting and disclosure has been happening for years in other parts of the world, and it seems logical that all regions of Canada get on board, at least offering voluntary programs to property owners seeking to learn lessons from such data.
Doug Picklyk dpicklyk@hpacmag.com
Ted Maulucci President, SmartONE Solutions Inc.
William
MacGowan, P.Eng., CEM Director, Digital Buildings, Industry Transformation Division, Cisco Canada
Bryan Jones Business Development Manager, Intelligent Building, Graybar Canada
Sponsored by
SAVINGS AT THE PUMP
Toronto’s Enercare Centre records significant energy savings with the introduction of variable frequency drives in the HVAC pump room.
With over one million square feet of exhibit and meeting space, the LEED Platinum-certified Enercare Centre at Exhibition Place in Toronto is the ninth-largest convention centre in North America. Located on the shores of Lake Ontario, the convention center experiences extreme weather—with temperatures ranging from −31C to 40C.
That puts a big burden on Exhibition Place’s HVAC equipment to keep the space comfortable for over 5.5 million visitors attending meetings, conventions and exhibitions throughout the year.
The amount of energy consumed for heating and cooling the space is significant—over 380,000 kW hours per year just to power the pumps that circulate chilled or hot water to fan-coil and air handlers throughout the facility.
As one of North America’s largest home and commercial services and energy solutions companies, Enercare Inc. has a commitment to energy conservation, so it’s no surprise as the venue’s naming sponsor it strongly supports Exhibition Place’s innovative GREENSmart program.
The program implements numerous committed energy and waste-reduction initiatives—which included retrofitting 11 pumps with Danfoss VLT HVAC Drives under Toronto Hydro’s PUMPsaver program. Completed in May 2018, the project reduced pump energy consumption by up to 38%. For qualifying facilities with closed-loop hydronic pumps, Toronto Hydro’s PUMPsaver program covered 100% of project costs, giving the Enercare Centre an immediate return on investment (ROI).
All images courtesy of Danfoss North America
A variable frequency drive on a pump in the boiler room at Enercare Centre.
Kildonan Energy. “The hydronics-system design employed constant-speed pumps in circuits using balancing valves that functioned like brakes to regulate fluid flow. As chilled or hot water circulates to fan-coil or air-handling units in the loop, the valves throttled open or closed to deliver the needed supply water.”
Sage notes that “using a balancing valve to regulate a constant-speed, constant-flow system is like keeping your foot on a car’s accelerator and tapping the brakes to control motion. It wastes a lot of energy.”
Many utilities provide various incentives to business customers to encourage installation of variable frequency drives (VFDs) for fans and pumps, according to Irina Sivryukova, administrative lead, energy services division of Kildonan Energy, and Rajiv Harnarain, B. Eng, CEM, also with Kildonan Energy’s energy services division.
Kildonan Energy specializes in turn-key engineered VFD solutions for HVAC, and served as the exclusive partner for the PUMPsaver program offered by Toronto Hydro from 2016 through April 2019. The firm completed over 650 projects under the program and continues to work with similar utility programs today.
How VFDs cut energy consumption
“Applying Danfoss VLT FC102 variable frequency drives dramatically improved pump motor efficiency for Enercare Centre,” explains David Sage, owner of
To improve energy efficiency, a variable frequency drive was added to each of the pumps in the system. The VFDs are designed to vary the speed of the motor, allowing the pump to match the system load requirements without the need for mechanical balancing valves. Using a flow meter to verify results, the VFDs are tuned back to match the existing flow of the system once the mechanical balancing valve is opened to its maximum position. By opening the balancing valve, the system resistance drops significantly and the power requirements are reduced.
A VFD solution not only eliminates wasted energy inherent in using balancing valves, it also runs the pump at its optimal efficiency points. Similar to how a car’s performance is measured in horsepower, torque and speed, a pump’s performance is measured in motor power (kilowatts or horsepower), speed (RPMs), head pressure (psi) and flow (gal/min). The physics
The Enercare Centre at Exhibition Place in Toronto.
of a rotating centrifugal impeller is most efficient at specific speeds, pressures and flows, creating points that can be graphically mapped as a “pump curve.”
The Danfoss VFDs used can not only run the pump motors at reduced speed, but also at the best efficiency points on the flow/ head pump curve. From the motor’s point of view, riding the pump curve minimizes wear and tear on the pump impellers and bearings and reduces operating noise levels. From the system’s view, the fan coil and air handling units see the flow rate and head pressure they are designed for.
From an energy point of view, the physics of Affinity Laws for centrifugal impeller pumps state that power consumption can be reduced by the cube of the change in speed. In other words, running the pump motor at four-fifths speed (80%) theoretically reduces power consumption by half (50%).
Not every pump application can take advantage of the Affinity Law for power. For example, applications using a valve to throttle the output flow will increase head pressure, which makes the pump work harder and wastes energy. In the Enercare Centre, this source of wasted energy has been eliminated. But pump performance was also enhanced because the drives were optimized to the pump curve.
Variable speed drives go with the flow
The drives used in this application com-
prise a broad family of variable-frequency drives (inverters) that can be applied to pump motors ranging from 1.5 to 600 hp. They are built on a modular plug-and-play platform to simplify setup and operation in HVAC applications. For the Enercare Centre, the drive’s built-in intelligence provided capabilities that include:
• Distributing running hours evenly across multiple pumps to minimize wear and tear on individual pumps.
• Minimizing harmonic distortion in the facility’s and utility’s electric grid with integrated chokes and radio frequency interference (RFI) filters.
• Limiting amperage draw when the pump motor starts without the need for a separate soft starter.
• Monitoring system reaction to speed changes with auto tuning to maintain required head and flow.
• Simplifying programming through a built-in smart logic controller that minimizes the need for a programmable logic controller (PLC).
In implementing the VFD solution at Enercare Centre, the team at Kildonan Energy were able to use the features of the Danfoss VLT drives to tailor a solution for the specific needs of both the application and the customer including allowing the operators access to the system function through Enercare Centre’s building automation system.
Chiller room pump at the Enercare Centre.
