We must look to the Authority Having Jurisdiction (AHJ) and all local code requirements to determine whether commissioning is required. Commissioning is most commonly addressed in the AHJ’s adopted energy code. For instance, the 2012, 2015 and 2018 versions of the International Energy Conservation Code (IECC) Section C408 indicate commissioning is required, and it is on the design professional to provide evidence of mechanical system commissioning completion, whereas ASHRAE 90.1 energy code does not explicitly require commissioning.
Energy codes can indicate commissioning exemptions based on the building’s heating and cooling system capacity threshold and building use. As an example, the following systems are exempt in the IECC:
Mechanical systems in buildings where the total mechanical equipment capacity is less than 480,000 Btu/h (140 690 W) cooling capacity and 600,000 Btu/h (175 860 W) heating capacity.
Systems included in Section C403.3 that serve dwelling units and sleeping units in hotels, motels, boarding houses or similar units.
So, if you have a building with less than 40 tons of cooling, or a building such as a hotel with PTAC’s, commissioning would not be required by the IECC.
It is the responsibility of licensed design professionals to understand all applicable codes and their specific requirements on every project.
For context on how often commissioning is required, 85% of projects completed by KCL Engineering in 2019 would require commissioning based on the IECC.
Bonus Content: Who holds the contract for commissioning services?
There are two traditional routes for contracting commissioning:
The owner may choose to hold the contract directly with the commissioning agent and manage the services.
The owner may choose to forego managing the contract and have commissioning services be contracted directly to the architect, general or mechanical contractor.
The commissioning agent is responsible for working as a cohesive unit with the design team, owner, construction team, and technical experts, and will schedule and coordinate commissioning tasks throughout the entirety of the project
Bonus Content: What is the value of commissioning?
Commissioning is a quality-focused professional practice to verify that a building’s new systems are properly installed and tested. Since site visits conducted by design professionals don’t include quality control beyond field observation, in-depth system testing through commissioning identifies issues and corrects deficiencies prior to occupancy, and helps ensure your building is operating as efficiently as possible, keeping your utility bill as low as possible. Because of those reasons, KCL recommends that all projects include commissioning.
Questions about commissioning services? Contact Matt Faber,PE (515) 512-3250
back to Ask An Engineer