Commissioning for Integrated Systems
The new Canadian Standards Association Z320 Building Commissioning standard that was launched in May is the first Canadian standard to take an integrated approach to commissioning.
“Previous standards looked at commissioning each system separately,” says Bill Carson of The Mitchell Partnership, a Toronto mechanical engineering firm. Carson was chair of both the CSA standard’s technical committee and its controls and integration sub-committee: “A number of stakeholders, primarily the Mechanical Contractors Association of Canada, have been fighting to establish a standard that not only looks at commissioning each independent system, but also ensures that each system works with every other system across all the trades, and disciplines, and particularly through the grey areas between them. That includes everything from mechanical, architectural, electrical, control and safety systems, to both horizontal and vertical building transportation, such as elevators and escalators.”
The new standard Z320 will apply to both new construction and building renovations. It was based on CSA Z318, Commissioning of Health Care Facilities, the standard it most resembles, because Z318 had made a pioneering effort to integrate fire safety, security and mechanical systems and their relationship to building controls.
“Using a hospital as an example,” says Carson,”you need to ensure that when the hospital issues a code for response to a heart attack, you also ensure that it integrates that call for help with an elevator arriving on the floor where the crash cart is located, and that [the call] would work under all conditions — in day, night, emergency and non-emergency conditions.”
Carson says that the new standard will offer obvious benefits to engineers by helping to ensure that the building functions according to its intended design before any wrinkles in its operation can cause problems.
“If the standard is applied, it helps to identify the intention of the design from the beginning, from pre-design to design and tendering, and ensures the project is built in compliance with the design and what it attends to accomplish right through the construction process,” he says. “It will also minimize the type of project dynamics — known more commonly as screw-ups — that fester a year later, as the owner comes back to the architect and engineer of record. The problems will be fixed beforehand in harmony with the engineer of record.”
The Z320 technical committee comprised 28 members representing a diverse slate of disciplines and interests.
“We achieved consensus on a large part of the main standard,” says Carson, “and then wrote a series of nine non-mandatory annexes written in mandatory language to cover more specific tasks. That way an engineer can, for example, state that you will use Z320 and that specific annexes will apply.”
The commissioning standard can be accessed electronically and includes web-based check sheets. The process begins with the software asking the user to answer questions about the systems involved.
“The system then formulates the questions that the commissioning professional needs to answer as part of the commissioning process,” says Domenic Bonavota P.Eng., vice president with Mulvey and Banani International of Toronto. Bonavota was chair of the Z320 electrical sub-committee. “You would get a different checklist, for example, if you had a vertical building that relied on pressurization rather than exhaust fans to evacuate smoke from a building. At a minimum you would be instructed to perform a full black-out test.”
Bonavota notes that the process isn’t intended to make commissioning “dummy-proof” but to augment an actual real-life run-through of the building’s systems prior to hand-over.
“We’ve heard of so-called paper commissioners who commission a building in theory without an actual run-through,” he says. “During the electrical black-out of 2003 we saw pumps designed to fuel emergency power generators failing to operate because the pumps themselves weren’t hooked to emergency power. A real-time commissioning process would have caught that.”
Formulating the checklist system to incorporate complex electrical and security systems was particularly challenging, says Bonavota, because of the deep level of integration required for newer buildings. Each system must be tested multiple times in pre-energized mode, in start-up mode, in fully functional operation for performance testing, and in emergency mode.
“If it’s the intent of the design to provide optimum climate controls, then we need to test to ensure that not only do the electric-powered sun shades re-orient themselves to provide optimum natural lighting and shield the building during the warmest part of the day, but also to ensure that the electric lighting system and air handling systems compensate for that,” says Bonavota. “The web-based checklist will guide you through that process.”
Certifying building commissioners
Up next will be efforts to create a certification authority to establish a curriculum to teach building commissioning and ultimately to certify building commissioners.
Currently, most construction projects specify that a registered professional engineer carry out commissioning, usually as part of a consulting engineering concern, notes Carson. “But it’s important that we support an independent third-party process where the commissioning engineer works for another company, or at the very least isn’t part of the same design team,” says Carson.
“Commissioning a building isn’t simply a peer review of another engineer’s work but a commitment to ensure that a building is constructed to function in exactly the way it was intended, as outlined in the original construction documents.”
While the standard will remain voluntary until referenced in legislation, Bonavota says Z320 has already been referenced in a number of requests for proposals.
“It’s only been a few months since it was launched and already the standard is gaining traction in the industry,” he says.
Development of the standard was funded by a consortium of stakeholders including the Mechanical Contractors Association of Canada, the Canadian Construction Association, Defence Construction Canada, Public Works and Government Services Canada, The Mitchell Partnership and Mulvey and Banani. cce
Peter Kenter is a freelance writer in Toronto.
“It will minimize the type of project
dynamics — more commonly known as
screw-ups — that fester a year later.”