Only an experienced Commissioning Agent would be able to predict the chaos and last minute confusion involved in getting an Acute Care Hospital started up, checked out and tested prior to the building’s Certificate of Occupancy. It goes something like this….. The big day has been two plus years in the making and it all started with the review of the Owner Project Requirements (OPR) and the Basis of Design (BoD). This was followed by a comprehensive review of the Mechanical, Electrical, Plumbing & Control System (MEP & C) drawings and specifications culminating in issuance of Design Technical Review comments. The purpose of the work thus far has been to identify any potential gaps in scope of work and coordination between trades, to make certain the project specifications clearly identify the technical requirements for the project, and verify that systems will properly integrate and work together in an efficient manner from the perspective of the Operator when all is said and done. After working through the technical review comments, the next step was to chair detailed sequence of operations workshops. The goal here was to get all of the interested parties to agree on and document the nuances associated with the sequences of operation for the various systems throughout the project. By having everyone on the same page, functional testing plans and control system programming can get started and work in parallel.
Now move forward nine months and even with all the upfront effort, you find that the equipment pre-functional checklists are incomplete, the control system contractor has not completed their point to point check-out or sensor calibration, the color graphic pages have yet to be submitted, etc., and time is drawing near for field testing of the control programming, which validates that the systems indeed operate to the sequences of operation. Your plan, which was developed with efficiency in mind, was to perform testing in the field only after all submittals were complete, and after the control contractor had demonstrated their work to the General Contractor. But that wasn’t accomplished and now there is no time left. The immediate need to get the project done far outweighs your plan that would have provided future benefits of proper system operation and decreased life cycle costs. So you move ahead with the field testing because, “you gotta do what you gotta do” to get the job done. Commissioning cannot be the reason for the job not getting done.
So what are some of the things that can pop up even though you and the project team thought you had covered it all in your planning and scheduling efforts?
You find that the graphic pages are not designed to allow the Operator or the Commissioning Agent to change set points in order to execute the functional testing, resulting in the contractor trying to make last minute on-the-fly changes, only to find the problems are too deeply rooted in the programming. In addition, you find that the graphical representations do not resemble the as-installed system.
You find that the building management system controllers are “going to sleep” and controllers are performing auto-calibration routines for heating hot water valve and air flow damper actuators that are not supposed to happen. Worst of all, these items were discussed and “resolved” in the sequence of operation workshops.
You find that the chilled water system is not staging properly for any one of a multitude of reasons, such as, setpoints have not been tuned properly, chilled water differential pressure transmitters are not calibrated, there is a problem with the control program that does not allow the chillers to start early enough without starving the air handling units of chilled water, etc., etc. As a result of the chillers not staging properly, the space humidity in critical areas is greater than the code allowed 60% RH because the AHU has no other means of de-humidification.
You find that the humidifiers are continually cycling on and off based on the humidifier’s supply air humidistat which you learn is not being monitored by the control system so it doesn’t know it needs to command the output to the steam valve to 0%Open. The result of this condition can be fog coming from the supply air diffuser, and if it’s blowing directly on the flat screen TV, condensate collects and drips onto the floor.
You find that the Negative Pressure Isolation Rooms are in continual alarm which may be caused by the Isolation Room or the Ante Room not being properly sealed above the ceiling, improper air balance, or doors without seals.
The lessons learned in dealing first hand with how to prevent and correct these issues, will be the subject of future blog postings.
How the team approaches and deals with the upsets is one of the keys that will make or break the project. In no case however, should up-front due diligence work be forfeited. It is extremely important and beneficial to identify potential problems and get those issues resolved. The upfront work pays dividends and should include updating contract documents to reflect, as close as possible, how the system is to perform at completion. Another often ignored key factor to project success is making certain that the project construction schedule is more than just a “brick and mortar” type of schedule. It needs to include detailed work tasks related to building MEP&C systems.
While this depiction of commissioning realties may sound discouraging, every Owner, General Contractor, and Commissioning Agent needs to realize that their best laid plans will experience upsets and challenges as the project nears completion. Bringing systems on line and verifying that they are working properly and efficiently takes time, effort, and dedication from multiple partners including the Manufacturer, Engineer of Record, Control System Contractor, TAB Contractor, and Installing Contractor(s).
Bringing Buildings to Life. It’s not just our motto, it’s our passion.
– Contributed by Brad Tuttle, Director of Commissioning Services, HTS, inc., BTuttle@consulthts.com