QSE Logo

LetsTalk2015@QSEng.com
612.308.4716

Starting Commissioning Late

As we’ve been defining commissioning in this column for the past 1-1/2 years, the greatest benefit from commissioning will be achieved by starting the process in the design phase of a project. Unlike many people’s perceptions, commissioning is NOT something that happens only at the end of a project. Testing is something which occurs towards the end of construction, and this is what many people consider “commissioning.”

Testing will verify that systems function as designed, but if there are any problems with system performance, testing is not a solution. The end of a project is a bad time to discover major deficiencies. The cost of correcting deficiencies is higher then than at any other time in the project, and there is very little, if any, budget or time remaining in which to perform the corrections.

Testing is clearly a key component of full scale commissioning, but it should be a simple “demonstration” of proper system performance, not a “close your eyes, cross your fingers, and hope this thing works.” The systematic process of commissioning is intended to significantly reduce the probability of there being problems at the end of construction.

Training is another key component of full scale commissioning which occurs towards the end of construction. This, both equipment training and system training, is critical to helping ensure that the systems will continue to operate properly and efficiently once they are turned over to the building owner to maintain.

So, what happens if you DON’T start commissioning in the design phase? The answer is that there will always be a benefit from commissioning, regardless of when it starts. The benefits, however, diminish as you start later and later in the project.

The most extreme case of “late” in my personal experience was being contracted to perform HVAC commissioning for an extremely complex and environmentally demanding building about 11 months into the warranty period. The design and construction team was top notch, and the owner felt that the team should be able to figure out and resolve the problems with system operation which were obvious based on trend logs, occupant complaints, etc. After almost a year of finger pointing amongst the design/construction team, the owner didn’t know what to think and brought us in as a third party commissioning consultant.

We were able to diagnose the problems, identify responsible parties, and define solutions to achieve the original design intent. The important finding was that there was no ONE responsible party for any given problem, and that led to all of the previous finger pointing. Everyone could see where it was someone else’s “fault” but couldn’t (or wouldn’t) see where their own responsibility lay.

Once we identified the causes and solutions to each problem, in a very technical and professional manner, it was up to the owner (our client) to decide what to do with that information. By that time the warranty period was over, there was no budget left in the project, and the solutions to some of the more challenging problems were extremely difficult and costly to implement. The owner chose not to pursue solutions to those problems, wanting to finally close out the project and get on with their core business without suffering through potentially long and drawn out suits against various “responsible” parties.

We were able, through control system software corrections, to achieve most of the environmental control performance criteria (i.e., temperature, humidity, and pressurization control). The systems that were not corrected at the time were some of the aggressive energy conservation features designed into the building. The owner spent extra construction dollars on implementing energy conservation measures which, in the end, didn’t work. That not only was a “waste” of the increased construction cost, but the anticipated ongoing operating cost savings were never realized.

The benefits realized by the owner in this case were:

  • Improved environmental control

  • Understanding of the building’s actual operating capabilities

  • Training of building staff in SYSTEM operation

  • Closure to a project which was dragging painfully on

  • Avoidance of a potential litigious solution to the “problems”

If commissioning were started earlier in the project, the benefits could have been greater:

  • Realization of more environmental control goals for the building

  • Ongoing energy cost savings

  • On time project completion and closeout

  • Positive experience, both professionally and economically, for all parties involved

I have seen a consistent trend in the building industry for owners to start their first commissioning project “late” – usually sometime during the construction phase. This is typically because, once the owner learns about and has decided to implement commissioning, there is always a project under construction that the owner thinks is a good candidate for commissioning. These owners find that it is certainly better to start commissioning late than to not do it at all, but they quickly realize how much more could be gained by starting during design. These same owners will start the commissioning of subsequent projects earlier and earlier until their protocol is to include the commissioning consultant amongst the first consultants hired for the project.

 

Commissioning: Getting It Right

Engineered Systems, May, 1999

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