Building commissioning (Cx) is an integrated, systematic process to ensure, through documented verification, that all building systems perform interactively according to the "Design Intent". The commissioning process establishes and documents the "Owner's Project Requirements (OPR)" criteria for system function, performance expectations, maintainability; verify and document compliance with these criteria throughout all phases of the project (design, manufacturing, installation, construction, startup, testing, and operations). Commissioning procedures require a collaborative team effort and 'should' begin during the pre-design or planning phase of the project, continue through the design and construction phases, initial occupancy phase, training of operations and maintenance (O&M) staff, and into occupancy (for warranty and future re-commissioning).
Historically, “commissioning” as referenced in building design and construction, referred to the process by which the heating, ventilation, and air conditioning (HVAC) systems of a building were tested and balanced according to established standards prior to the Owner's acceptance. HVAC commissioning, historically, didn't include other, interactive, supporting, or supplemental building systems that did not directly affect the performance of the HVAC systems.
Through energy and water conservation, occupant comfort, life-safety, systems criticality, and technology improvements of building systems became more in demand, and expanded the Owner's performance and technical capability expectation. The need to improve, integrate, and commission other (and more) systems expanded the scope of Building Commissioning. In modern facilities, buildings, and systems many of the systems are integrated (directly or indirectly) in operation, affect, need for proper operation, function, control, and sequencing. This can become very complex, and provide many points of sub-optimal operation, or failure, with all the many systems requiring, or affecting, interaction of each other.
For example, power sources (utility, generation, battery/cell) control and monitoring, air movement control, smoke control, fire suppression, fire alarm, security door egress/evacuation control, elevator control, space containment/infiltration, staging and sequencing of every interacting system, it's sub-system, equipment, and components each operating and interacting correctly in every operating Mode (normal, startup, shutdown, maintenance, economy, emergency, ect.).
This list can go well beyond this example, even in the most basic, typical, facility today. As more building systems are integrated, a deficiency in one component can result in sub-optimal operation and performance among other components and systems. Through system testing and "integrated systems testing" (IST) verification of all interrelationships, effects, modes of operation, and performance can be verified and documented to comply with the 'Owner's Project Requirements' and Architect/Engineers documented 'Design Intent' performance.
Thus, 'Whole Building Commissioning' (or 'Total Building Commissioning') is the accepted normal/standard, certainly for government and critical facility Owners, but also for conservation and efficiencies to provide a fully verified operational facility. Partial building commissioning (commissioning only specific equipment, functions, systems) is also still utilized, but the interrelations of many automated systems, as designed, today branch and spider throughout many other systems within even basic buildings. The Owners Project Requirements and the Architect/Engineers design should clearly identify the scope and expectations of commissioning.
View More On Wikipedia.org