Traditional building commissioning (cx) relies on proven processes to ensure seamless and efficient facility operation. However, today’s climate is forcing a change — with a higher demand for buildings and the increased need for speed to market, construction teams are employing different methods within modular construction to rethink the traditional process by redefining the levels to reduce cost and schedule.
The Traditional Process
The tried-and-true cx process that most are familiar with — based on ASHRAE Guideline 0 — outlines the following levels.
- Level 0 — Design and planning phase for cx input to ensure the documents are in line with the client’s intended facility usage.
- Level 1 — Factory witness testing to verify test plans comply with design requirements.
- Level 2 — Site acceptance and installation to visually guarantee equipment has been received in good condition and ready for energization.
- Level 3 — Pre-functional startup, which includes inspection, energization, and startup of standalone equipment.
- Level 4 — Functional testing to verify equipment dynamically performs in compliance with design requirements.
- Level 5 — Integrated system testing (IST) is completed to test the facility as a whole.
While the consistency and established guidelines of the traditional process make it reliable, there are some things to consider when it comes to the overall methodology. The biggest obstacle when employing the traditional process is that the majority of the work is performed on-site, thus creating schedule delays. Commissioning does not start until construction is complete. Any project delays multiply and push the schedule, with little room to adjust and compensate for lost time. Additionally, factory witness testing is primarily performed on major equipment, which only tests one-of-a-kind types of equipment rather than testing all of the equipment. These are some of the reasons modular construction is emerging as a viable option for mission critical projects moving forward.
A Case for Modular
More construction is moving off-site to utilize modular solutions. It offers more flexibility in scheduling as well opportunities for cost savings. With all parties present off-site, it is a more efficient use of time, reducing labor costs by increasing collaboration and communication. Additionally, it condenses the number of external factors that can interrupt testing — for example, confusion on Lockout/Tagout (LOTO), delivery issues, equipment damage, and trade stacking. While the integrators are building the equipment skids in a protected space, it is the optimal time for the cx team to perform a combined version of Level 2 through 4 with all relevant parties. Taking it to an even more finite level, executing smaller work packages makes the work repeatable, easier, and faster for the trades executing the work.
Shortening the Process
The opportunities to further shorten the process when using modular construction extends to testing. If testing is already performed at an integrator or facility, then it eliminates the need to repeat the testing again on-site — as is the case with load testing that has typically already happened at the factory. The benefit of having the skids preassembled at the integrator is the commissioning team gains the opportunity to test the assembly on temporary power, as individual parts, and as a whole before it ships. When the equipment arrives on-site, it can undergo a visual verification and quality checks in addition to receiving permanent power as a final check before performing IST.
Why it Works
Modular construction offers clients familiarity and repeatability for equipment while also providing opportunities to troubleshoot without risking the schedule and adding cost. When working with the same clients and the same equipment configurations, the expectations for testing remains consistent. Project after project, issues always arise due to firmware upgrades, breaker sizing, breaker settings, BMS controls, arc flash labeling, etc. By performing most of the commissioning off-site at the integrator, these issues can be resolved much more efficiently and allow for more time to focus on the IST on-site. The time saved by working as lean as possible condenses commissioning activities by eliminating a step, saves owners money, and improves speed to market.