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Deciding How to Commission What

When developing a Commissioning Plan for a specific project, each facility owner needs to decide what the scope of commissioning will be. There are two basic questions required to define the scope of commissioning:

  1. Which Systems will be commissioned? And

  2. Which commissioning Tasks will be applied to those systems?

This month we will consider the first of these questions. Next month, we will tackle the second.

With respect to the Systems to be commissioned, the following factors play into facility owners’ decisions:

1.  Where have problems consistently occurred on past projects?

Every project manager knows which systems have given him/her the most trouble over time. Practically no facility owner can afford to commission every system in a building project, and they always prioritize around the question of which systems need the most help.

2.  What are the risks of system malfunction after occupancy/beneficial use?

Even if a system type has not historically been a problem in the past, can the current project afford the risk of having it not work? For example, a stand-alone exhaust air system is typically not problematic in most projects. Even if a simple exhaust system does not perform exactly right at substantial completion, the risk might simply be an offensive odor problem which can quickly be identified and addressed. However, in a negative pressure isolation room application in a hospital, even the tiniest risk of non-performance upon occupancy is unacceptable, and most of our clients would choose to commission the exhaust system and its interactions with other building systems.

3.  What are the political implications of poor system performance?

This goes back to the individual project characteristics. A client may choose not to commission simple fan-coil units in a standard classroom/office building, but they will almost always commission the fan-coil units serving the President’s office suite.

4.  How easily would deficiencies be found without commissioning?

If a system problem will be readily apparent during the first few days/weeks of occupancy and use, it may not be a valuable candidate for the rigors of commissioning. Commissioning is partially focused on ferreting out - with relatively rigorous procedures – operational deficiencies before they become operational problems. There is typically no need to spend time and money on rigorous procedures, if simply using the systems for a short time will result in discovering the deficiencies. At that point, the installation contractors should still “engaged” in the project and will be available and, hopefully, willing to correct deficiencies under their warranty and/or punchlist obligations.

Examples of systems that fall into this category include manual light switches, plumbing fixtures (toilet flush valves, faucets, etc.), and normal power electrical outlets.

5.  How many parties are involved in design and construction of a single system?

The more contractors and/or subcontractors who have responsibility for a system, the more important it is to commission that system. As implied in the previous paragraph, if a problem is discovered in a simple system (i.e., single point of responsibility), a typical project delivery process has mechanisms for getting it fixed by the responsible party.

However, as soon as a building owner finds a problem with a system where multiple parties were responsible for making it function, the building owner does not get a quick fix-it response – he/she gets a lot of finger pointing and nobody willing to correct the deficiency. One of the most complex systems is an HVAC air handling system which often requires coordination and cooperation between the sheet metal contractor, pipe fitter, electrical contractor, controls contractor, insulator, VFD-supplier, test & balance contractor, and fire alarm contractor. Having a third party commissioning provider who can readily identify an operational deficiency and provide input as to its root cause can save scores of hours in meeting, correspondence, and (worst case) litigation time and expenses.

In summary, there are no standard lists of systems which should be commissioned on every project. Each project owner needs to thoughtfully consider the above factors along with budget constraints when developing the list of systems subject to the rigors of commissioning.

 

COMMISSIONING: GETTING IT RIGHT

Engineered Systems, December, 2004

by
Rebecca Ellis, PE, LEED AP, CCP, CxA
President
Questions & Solutions Engineering
1079 Falls Curve
Chaska, MN  55318
rteesmag@QSEng.com