Babel Buster Network Gateways: Big Features. Small Price.
Jim Sinopoli PE, RCDD
Author of "Smart Buildings"
Commissioning of building systems has never been as critical as it is today. Why is that? There are several reasons:
• At the top of the list is the concern for energy usage. Less than optimum performance of HVAC, lighting control and power management systems translates into inefficient energy usage, increased energy costs and higher maintenance costs.
• Second is the range of building technology systems that are now normal components of a project. The traditional, one-time commissioning of just the HVAC and HVAC control system is long gone. Commissioning now involves security systems, fire alarm systems, fire suppression systems, telecommunications systems, information technology systems, etc. More importantly, it involves the complexities of system integration and their interdependence.
• Third is the impact that commissioning can have on the management, operation and maintenance of the facility. If commissioning can produce even small improvements in the efficiencies and effectiveness of operations, the result will be significant lifecycle cost savings.
Some building owners shun commissioning, not understanding the value, not understanding how independent commissioning is different than contract administration or activities performed by the design team or contractors, and viewing commissioning outside of the core requirements and budget of the building.
The following is an overview of the impacts of commissioning on energy use, the traditional approach to commissioning, total commissioning, and the benefits of integrating commissioning into complete process of building design, construction and operation.
Impacts of Commissioning on Energy Use
Many building technology systems that are installed in new construction still perform at sub-optimal levels. Surprisingly, a DOE sponsored study found “The need for commissioning in new construction is indicated by our observation that the number of deficiencies identified in new-construction exceeds that for existing buildings by a factor of three.” It sounds counterintuitive but it’s a reflection of common and pervasive design flaws, construction mistakes, and faulty equipment. For existing buildings, the problems are compounded by deferred maintenance. One of the major effects of these conditions is increased cost of energy and system maintenance, both of which impact operational costs of the building. Commissioning is the activity which can rectify this situation.
A December 2004 study sponsored by the US Department of Energy provides insight as to the effect that commissioning can have on correcting these deficiencies. The report titled “The Cost-Effectiveness of Commercial-Buildings Commissioning” is an analysis of energy and non-energy impacts in existing buildings and new construction in the US. The study examined 224 buildings across 21 states, representing 30.4 million square feet.
While the study results were conservative (not all building systems were included or commissioned) it found that commissioning for existing buildings resulted in energy savings of 15% with a payback time of 0.7 years. New construction yielded a median payback of 4.8 years. One-time non-energy benefits averaged $0.18 sq. ft. per year for existing buildings and $1.24 sq. ft. for new construction. Non-energy benefits included extended equipment lifetime, improved thermal comfort, decreased service call incidence, improved indoor air quality, first-cost reductions, labor savings, improved productivity and safety, decreased change orders and warranty claims, and liability reduction.
It’s clear that there is value to commissioning, with commissioning resulting in both capital and operating cost savings.
For many construction projects, traditional commissioning is a one-time activity conducted right before the keys to the building are handed over to the owner. Unfortunately, it typically comes at a time when the owner is busy preparing to move people and equipment into a building, and there’s a flood of other close out issues facing the owner.
The scope of such traditional commissioning is primarily focused on HVAC and HVAC control systems, essentially validating, verifying and measuring the systems against the design intent of the mechanical engineer. The tools for traditional commissioning are typically paper checklists. Traditional commissioning is generally focused on assuring the system components are properly installed and operating. It may involve testing, balancing and adjusting the systems, reviewing and approving O&M manuals, etc.
Note that there is a difference in commissioning and contract administration. Contract administration is performed by the design team and is verifying what’s installed against the contract documents. Commissioning is more associated with verifying the installation and operation against the owner’s requirements.
Total commissioning integrates commissioning into the total life cycle of a facility, with commissioning activities occurring throughout the design, construction and operation of the facility. It covers all of the building technology systems. It involves integration of the systems as required, and uses software programs rather than paper checklists to make the most effective use of the data and information created, gathered and stored.
Total commissioning starts early in the process. A commissioning agent is brought on board by the owner during the “concept phase” of the facility, and joins the team that is developing the facility’s program. The agent is independent of the other team members and is focused on how to document the owner’s requirements and defining the performance criteria which eventually will be measured during the systems’ commissioning. Input by the facility manager is important at this early stage as well. The facility manager’s input and participation during the commissioning process will improve the commissioning agent’s work and can provide more relevant information for the building operations and maintenance.
The requirements from the facility program and conceptual phase form the basis for the design. During the design phase, the commissioning agent checks to make sure that the system requirements and measurable criteria are incorporated into the design. In many cases this goes beyond the building technology systems. Assume for example, an owner wants office space to be at 70°F with 28% relative humidity. The commissioning agent will examine the design of the HVAC and lighting control systems, but also window treatments, insulation, glazing, etc.
The design phase will produce specifications, and the construction specifications can address issues related to commissioning. In CSI’s MasterFormat 2004, there are several places where commissioning is addressed. Division 1-General Requirements cover both lifecycle activities and the commissioning agent. In the life cycle sections the requirements for system performance are specified and the responsibilities of not only the commissioning agent but also the contractors are itemized. These references focus on the facility substructure (foundation and basement), the shell (superstructure, exterior enclosure and roofing) and interiors (interior construction, stairways and interior finishes). In addition Division 1 addresses requirements for facility operation and maintenance. Division 25-Integrated Automation, Division 27-Communications and Division 28-Electronic Safety and Security, all address commissioning of their respective systems.
During the construction process, the commissioning agent monitors changes and how they affect the owner’s requirements, essentially providing quality assurance and control. These changes may involve material or equipment substitutions by the contractors, shop drawings, change orders, contractors’ request for information, directives, supplemental instructions, etc. The agent is involved with equipment start-up and operational testing and the systems’ transition into the hands of the facility manager and plant operator. More importantly, the commissioning agent checks against the owner’s requirements identified in the conceptual phase.
The primary purpose of total commissioning is to ensure that the completed facility operates as originally intended. The information gathered during the commissioning process assists the facility manager in operating and maintaining the facility’s systems. (Keep in mind that the data and information created during design and construction is typically under-utilized and under-valued).
Information the commissioning agent creates is critical when establishing an O&M program for the facility. The agent can provide information on routine maintenance, test reports, load testing, start-up data, equipment lifecycle, operating adjustments, training requirements, spare parts, etc.
Commissioning needs to be a continuous building process, from conception through operation. The effectiveness just in energy costs is impressive. For owners, commissioning results in fewer change orders, reduced operating costs and fewer construction delays. For facility managers commissioning provides properly operating systems, fewer tenant complaints, better staff training and better documentation.
For more information about smart buildings, technology design or to schedule a Continuing Education program for your office write us at email@example.com
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