The benefits of commissioning include reduced energy use, lower operating costs, reduced contractor callbacks, better building documentation, improved occupant productivity and verification that the systems perform in accordance with the owner’s project requirements. With so many potential benefits, it’s baffling that a number of owners still decide not to commission their buildings.
What is commissioning?
One thing that makes a LEED-certified project different than most non-certified buildings is that the certified building goes through the process of commissioning. When a building is commissioned, a designated individual (the commissioning authority) verifies and documents that a building and all of its systems and assemblies are planned, designed, installed and tested.
The commissioning authority also verifies that training has been completed so that the equipment can be operated and maintained to meet the owner’s project requirements. In practice, the commissioning process is a systematic quality assurance or quality control program. It is a focused effort to ensure that building systems are designed, specified, procured, installed and functioning in accordance with the owner’s intent. The process uses planning, documentation, and verification of testing to review and oversee the activities of both the designer and constructor.
There are several levels of commissioning. In LEED terms, there are three distinct types of commissioning: fundamental, enhanced and whole building. Under the current version of the LEED rating system, fundamental commissioning is a prerequisite, and it requires the commissioning authority to verify the functionality of the basic energy consuming equipment in the building. This would include HVAC equipment, hot water heaters, lighting, lighting controls and water fixtures.
Enhanced commissioning adds to the activities found within fundamental commissioning, but the process starts earlier, in part, because a minimum of one design review must take place prior to the completion of design documents. The commissioning process continues with the commissioning authority reviewing the submittals for all equipment to be commissioned. Whole building commissioning applies the process to the entire building, including the building envelope.
When should a building be commissioned?
The commissioning process should begin early in the delivery process, beginning with the development of the Owner Project Requirements (OPR), which is a written document that details the ideas, concepts, and criteria that are determined by the owner to be important to the success of the project. This document is then used by the designers to develop the Basis of Design (BoD), which includes design information necessary to accomplish the owner’s project requirements, including systems descriptions, indoor environmental quality criteria, design assumptions, and references to applicable codes, standards, regulations and guidelines.
Once the OPR and the BoD have been established, the design team can begin their work. Midway through design, the commissioning authority will complete a review of the design and comment on any item that may not achieve the owner’s requirements. Once the construction begins, the equipment and systems submittals will then be reviewed prior to purchasing equipment.
Throughout the construction phase, the commissioning authority will make periodic visits to the site to review the installation of systems and equipment. After the installation of the equipment has taken place, the commissioning authority will witness the functional testing of the equipment or systems and then will verify that training of the facility operator(s) has taken place and that the level of training is appropriate for the types of equipment or systems that have been installed in the building. All of the related operation and maintenance manuals will then be reviewed to create an overall systems manual for the facility operator.
Why commission a building?
Even with the demonstrated benefits, there are still many owners do not see the need for commissioning. These owners feel that by hiring someone to design their projects and hiring a contractor to build the projects per the plans and specifications, there is no need for a third party to commission the systems that are in the building. But, due to no fault of the designer or contractor, mistakes can sometimes happen. There are other instances where the work is designed and installed per the specification, but the equipment does not function as it was intended.
Recently on a project site during commissioning, there was a situation where the mechanical contractor had purchased the correct equipment and installed it per the design documents. When the equipment was turned on for the commissioning process, it was observed that the discharge from the unit went directly onto a conveyor that had also been installed per plan and specification.
In this instance, both contractors had performed their work to plans and specifications. However, due to a lack of coordination between the mechanical contractor and the conveyor installer, the equipment would not function as intended. The solution to this problem was to rotate the piece of equipment so the discharge warmed the space and not the conveyor.
Commissioning the systems within the building or the entire building can have a lasting impact on the way a building performs, potential energy savings and the operations and maintenance of a building. A savvy building owner realizes the value of commissioning and the process that it entails. Regardless of LEED certification, a building owner can benefit from building commissioning.
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Thomas Taylor, a 30-year veteran of the construction industry and noted expert on sustainability, is a principal and co-founder of St. Louis-based Vertegy LLC. To learn more about Vertegy or Taylor, visit www.vertegyconsultants.com.