Commissioning-CX

Commissioning-CX

SERVICES

Certificates

Commissioning (CX)

Commissioning is the process of verifying that a building’s energy-related systems and equipment are

LEED CX

In the last few years, commissioning of the commercial buildings and residential homes has gained popularity through a growing interest in energy-conservation and the popularity of the LEED green building rating system. Since the emergence of commissioning in other realms, our certified commissioning agents have expanded our commissioning resume to include high-rise buildings, university buildings and classrooms, hospitals and health care facilities, theaters, recreational facilities, and corporate campuses, residential homes, and so on.
The United States Green Building Council (USGBC) began development of the Leadership in Energy and Environmental Design (LEED) rating system in 1994 as an independent, third party certification program to serve as a "benchmark for the design, construction and operation of high-performance green buildings (www.usgbc.org).

The rating system is composed of six different categories: Sustainable Sites (SS), Water Efficiency (WE), Energy and Atmosphere (EA), Materials and Resources (MR), Indoor Environmental Quality (EQ) and Innovation and Design Process (ID). The number of credits that a building earns determines the achievement one of four rating levels: Certified, Silver, Gold or Platinum. There are also a number of prerequisites, which every building must earn, to be eligible for a LEED rating. One of these prerequisites is Fundamental Commissioning, as the USGBC has recognized that commissioning is essential to create an efficiently running building.
LEED EA Prerequisite for Fundamental Commissioning
In order to ensure that this process goes smoothly, the USGBC has outlined a series of deliverables required to satisfy the Fundamental Commissioning prerequisite for LEED:
     * Designate an individual not directly responsible for project design or project management as the Commissioning Authority (CxA) to lead the commissioning process activities.
     * The owner shall document the Owners Project Requirements (OPR) and the design team shall develop the Basis of Design (BOD) for the projects energy-related systems. The CxA shall review these documents for clarity and completeness.
     * Develop and incorporate commissioning requirements into the construction documents.
     * Develop and utilize a commissioning plan.
     * Verify the installation and performance of energy consuming systems meet the OPR and BOD.
     * Complete a summary commissioning report.
LEED EA Credit 3 Enhanced Commissioning
In addition to the prerequisite for fundamental commissioning, the LEED system also offers the option for earning a point for additional commissioning activities. This Enhanced Commissioning credit (Energy and Atmosphere credit 3 in LEED for New Construction) requires added commissioning services:
     * Designate an individual independent of the firms represented on the design and construction team as the CxA to lead the commissioning design review activities prior to the start of the construction documents phase.
     * The CxA shall conduct, at minimum, one commissioning design review of the OPR, BOD, and design documents prior to mid-construction documents phase and back-check the review comments in subsequent design submissions.
     * The CxA shall review contractor submittals applicable to systems being commissioned for compliance with the OPR and BOD.
     * Develop a systems manual that provides future operating staff the information needed to understand and optimally operate the commissioned systems.
     * Verify that the requirements for training operating personnel and building occupants are completed.
     * Assure the involvement by the CxA in reviewing the building operation within 10 months after substantial completion with O&M staff and occupants. Include a plan for resolution of outstanding commissioning-related issues.
Responsibilities of SALTecc as a Commissioning Authority (CxA);
As a CxA, it is imperative to understand the goals of the commissioning process as well as the requirements of the USGBC. With so much commissioning work coming from LEED projects, having a CxA that is experienced and well-versed with the system makes the commissioning process go much more smoothly. With the help of LEED Accredited Professional, SALTecc has an experienced staff to address the LEED requirements of the commissioning process. However, regardless of whether or not the project is pursuing LEED certification, the ultimate goal of commissioning is to ensure that the building is running efficiently, and as the owner and design team intended
 

 

RE-COMMISSIONING (Re-Cx)

The term Re-Cx is a confusing and often misused term. Simply put, Re-Cx can occur only if a building was commissioned at some point in its life. Once a building has undergone either building commissioning as part of new construction or retrocommissioning as defined above, the periodic Re-Cx ensures that the original results persist. Therefore, Re-Cx is a periodic event that reapplies the original commissioning tests in order to keep the building operating according to design or current operating needs. In the best of worlds, Re-Cx becomes part of a facility’s ongoing O&M program. Re-Cx may need to occur only every 3 to 5 years. However, the frequency of Re-Cx should be based on the complexity of the systems involved and the dynamic needs of the occupants. If there are frequent build-outs or changes in building use, Re-Cxshould be applied more often.In addition to that, the importance and effectiveness of Re-Cx is dependent to follow the 1stnew construction Cx documentations and follow up maintenance logs.

During Re-Cx process,
Through in-depth staff interviews and field investigations, our team may discover several ways in which the building could reduce energy consumption without making major changes to the systems' infrastructure.
The following measures are being structured and coordinated with ongoing expansion and modernization projects, so as to best integrate with master and capital planning and resource allocation:
     * Confirmation of duct static pressure controls and installation of isolation dampers on elevator shaft vents. This serves to eliminate the stack effect in elevator shafts and the resultant continuous loss of conditioned air and pressurization control.
     * Correction of damper actuator applications at air handling unit (AHU) outdoor air louvers to improve ventilation control.
     * Calibration and consolidation of outside air temperature sensors to optimize load sensing and central equipment lock-out strategies.
     * Replacements of all failed fire-smoke damper actuators that hinder adequate air flow and contribute to control problems.
     * Recalculation of airflows for all spaces within the building. This was done to reduce air changes per hour to levels that meet code while also reducing fan energy at the central air handling units, and also to address usage modifications at various zones.
     * Testing and balancing, including measuring flows at all VAV boxes and adjusting terminal units in a space-by-space engineering study of each zone based on usage.
     * Implementation of several low-cost programming changes at the central control terminal, including:
     * Loop-tuning chilled water valves for better control of supply air temperature.
     * Resetting supply duct static pressure based on multiple VAV box demand.
     * Resetting supply air temperature based on outside air temperature.
     * Revision to the airside economizer sequence.

Some of the lessons learned from our work providing facility optimization services to our clients include:
     * Facility needs for code compliance and operational improvements are often more important than the desire for energy savings.
     * The ability to combine energy modeling, design assessment and commissioning services under a single umbrella are of particular value to many clients.
     * Traditional energy service company (ESCO) approaches to facility audit and Re-Cx and Retro-Cxare often not geared to client strengths and are subsequently off target or over-priced. Our facility optimization services approach allows our clients to select various delivery methods for each measure (such as a simple design/build narrative for competitive pricing, to full design and construction management) as appropriate. This reduces labor cost and the need for outside financing, while incorporating risk mitigation measures that bring additional cost-avoidance benefits and value to the project.
 

 

RETROCOMMISSIONING (Retro-Cx)

To improve buildings and capture the sizable opportunities that exist within them, commissioning principles are being applied to existing buildings more and more often. Fortunately, commissioning of existing buildings—also known as Retro-Cx—when appropriately applied goes beyond quick-fix solutions to systematically optimize building systems so that they operate efficiently and effectively, often eliminating the need for costly capital improvements. Not only does Retro-Cx identify problems that occurred at construction just as traditional commissioning does, but it also identifies and solves problems that have developed during the building’s life.

SALTecc shall provide a comprehensive audit and retro-commissioning report for HVAC, electrical, and plumbing systems at the facility inspected. Our services leverage the Owner’s in-house capabilities and staff availability to keep scopes consistent and cost-effective. Our report has helped define a range of savings and improvement options by way of utility bill analysis, site walks and investigation of the building automation system.

“Do my existing buildings need commissioning?” an owner may ask. Many existing buildings are limping along in terms of performance, and unfortunately, most owners don’t know it. As long as building systems maintain a reasonably comfortable environment, nothing appears to be wrong. Many problems are noticed only when a catastrophic failure or a visible consequence occurs. For example, when unnecessarily large volumes of outdoor air are drawn into a building, excessive heating and cooling energy are used. As long as the heating and cooling systems have the capacity to handle this increased air volume, however, the problem goes unnoticed. Other common problems that drive energy costs up but may or may not cause comfort or other visible problems include;
     * Adjustable speed drives that are no longer adjusting appropriately,
     * Time clocks that are circumvented or set up improperly,
     * Equipment that is running more than necessary or running inefficiently because of improper operating strategies,
     * Energy management systems that were never installed or programmed to take full advantage of their capabilities or that have degraded over time, and
     * Controls that are out of calibration or are improperly sequencing.

Retro-Cx is widely applicable because operating and maintenance (O&M) problems are very common in buildings. Commissioning can benefit the “good, the bad, and the ugly” building. Which building type do you have and which type benefits the most from Retro-Cx? The bad building has numerous, obvious, and often complex O&M problems. It usually has attractive Retro-Cx opportunities. The ugly has these combined with needs for major capital improvements. Commissioning for both the existing equipment and new equipment is a good choice for this building type. Although “the bad and the ugly” stand to achieve the most benefit from Retro-Cx, the so-called “good” building often has lots of improvement potential as well, especially where multiple and more complex systems are used. Numerous well-designed, -constructed, and -operated buildings have major cost-saving opportunities. Often these opportunities are invisible to the owner but readily detectable through Retro-Cx. In most cases, energy savings alone makes Retro-Cx an attractive business investment.