Functional Testing Can Be a Waste of Money Without Design Review – Case Study

We received a call from a client seeking “commissioning.” Their project was already in construction, and they thought commissioning meant “functional testing.” We explained why functional testing without design review is a waste of money.

During testing, we might be able to find issues, but by then it may be prohibitively expensive to fix or we might not be able to test at all. We explained that it was a risk we weren’t willing to take and suggested doing a design review as a start. After hearing the explanation, they agreed.

We did the design review of the permit set. What we found went way beyond what we were expecting to find. A few broad examples:

  • Sequences that were inappropriate:
    • Duct static pressure reset for an air handling unit with no downstream terminal units. Same for the bathroom exhaust fan.
    • Differential pressure reset on a pumping system with 3-way valves on the air handling units; done for both hot and chilled water systems.
    • Mixed air damper sequence for an air handler with no mixed air damper.
  • Things that wouldn’t work with the hardware provided:
    • Points required for sequences not shown on the plans. Sequences can’t work without the right inputs.
    • Very outdated lighting controls/system specifications with nonexistent manufacturers and a sequence of operation that couldn’t be programmed because it either had no setpoints, the hardware wasn’t shown on the plans, or both. It even required a “CRT monitor” be provided.
  • A lack of QC.
    • Equipment on flow diagram not on plans.
    • A large amount of spelling and other unforced errors.

When we see a design of this quality, we see how valuable design review can be to clients. Overall, there were 25 pages of comments with over 50 comments (most high priority); many were multi-part comments. Not to mention that we wouldn’t have been able to test at all because the sequences either couldn’t be programmed or the equipment/hardware wasn’t there. Even if you are confident in your design, think of design review as an investment in your project’s success and long term operability. If you need help with commissioning, contact us anytime.

This case study was originally shared in kW’s Internal Commissioning newsletter published by Lyn Gomes.

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