Best Practices for Purchasing and Specification
Editor's note: The following is based on “Best Practices for Specifying and Purchasing Commissioning for Schools,” which Ron Wilkinson, PE, LEED AP, presented during HPAC Engineering's seventh annual Engineering Green Buildings Conference, held Sept. 23 and 24 in Baltimore as part of HVACR Week. For more information on HVACR Week, go to http://hvacrweek.com.
The commissioning (Cx) quality-assurance process is especially important for schools not only because our children deserve the healthiest and most productive indoor environments, but because in many parts of the United States, Cx is mandated by law for public and private educational facilities. What's more, school expenses are under increasing scrutiny, and Cx is an important part of minimizing energy use. Although Cx is used widely, there is no systematic approach to specifying and purchasing it for the best results at the lowest price.
This article will provide best practices for developing requests for proposals (RFP) for school Cx. A concise and complete RFP is the first step in an effective quality-assurance process for schools.
Since 2000, New Jersey School Construction Corp. has contracted with the New Jersey Institute of Technology to provide guidelines for the best schools in the United States. One facet of this endeavor is the creation and ongoing improvement of a school Cx RFP template. The template includes ASHRAE standards, the Leadership in Energy and Environmental Design (LEED) Green Building Rating System, California commissioning guidelines, and the U.S. Department of Energy's/Portland Energy Conservation Inc.'s “Model Commissioning Plan and Guide Specifications.” The template provides Cx purchasing guidelines for laypeople who frequently purchase technical services for schools.
The first lesson to learn about preparing a school Cx RFP is that it is not a brainstorming session. When a non-technical school board is tasked with specifying Cx, there is a tendency to pass the RFP around the room and add everything mentioned to the scope of work. The inevitable result of this is misunderstanding on the part of participating Cx providers (the Cx authority [CxA]) and “sticker shock” when the school board receives the proposed fees.
Cx can be applied to any part and system in a building, but that does not mean it should be applied to all parts of every project. For example, if the local fire marshal will witness demonstrations of the fire-alarm and fire-suppression systems, there may be little benefit to adding this to the Cx scope. On the other hand, if the school district has had problems with this in the past and the fire marshal has not helped, it might be good to add.
If state energy-office or utility-incentive programs are used to help pay for Cx, the tasks and equipment required by said programs must be included. Cx also can be funded by property insurance and tax rebates — and in some cases, Cx is mandatory when such funding is obtained. Certain Cx items, such as systems manuals, lessons-learned meetings, off-season testing, and as-built documentation, are required by some programs.
The point is that Cx is owner-driven, and Cx scope as requested in an RFP must reflect the owner's considered, discussed, and thought-out needs. The owners must understand the process, define why they are doing it, and explain what they want out of it.
Commissioning proprietary systems — security, specialty lighting (such as for a theater), telephone, and closed-circuit audio/video (such as closed-circuit television) — is outside the scope of LEED Cx requirements. Therefore, it should not be part of a LEED Cx RFP, unless the owner has a specific reason. If the owner wants Cx for proprietary systems, he or she should check the bid package to see if it already is part of the installing subcontract. If it is, having the CxA witness the testing will be less expensive than arranging the testing from scratch. Adding this clarification to the RFP can result in a lower fee for the overall project. Note the difference between this scenario and HVAC testing, which almost never requires real, documented Cx of the installed system by the installing contractors. This is especially true when systems, such as boilers, pumps, air-handling units, and perimeter heat, overlap.
It is important to hire the CxA as early in the project as possible. The best time to bring the CxA on board is immediately after the design team is hired, during the pre-design phase of a project.
Although little may be known about the actual structure, a full programming document should be completed by the time the design team is hired. The document will outline the square footage of the building (plus or minus 10 percent), the various occupancies, food service, laboratories, gymnasiums/pools, special features, materials, number of stories, phasing, budget, schedule, the level of LEED certification required (if any), and the level of energy efficiency, quality, and longevity required. This description, along with the systems to be commissioned, gives the CxA a basic outline from which a reasonably accurate fee can be generated.
This procedure can be refined, allowing the CxA generate a proposal for a project in two phases: design and construction/occupancy. The design-phase Cx scope mostly includes documentation and is less dependent on a square footage and actual installed systems than Cx that occurs during construction. The fact that about 25 percent of a Cx fee is expended during design and 75 percent during construction further minimizes the impact of small errors in fee estimation during the design stage.
Toward the end of design, when a job is being bid by contractors, the owner and CxA can revisit the CxA's initial construction-phase fee proposal and negotiate, if necessary. If there is a complete impasse in establishing a fair fee for the construction phase, the owner can solicit new proposals from scratch. This seldom is required.
Fee often is the most important criterion in CxA selection, but it never should be the only one. The Brooks Act mandates consultant selection based on competence, and most state and local procurement laws follow this procedure. A Cx selection-criteria matrix that gives credit for lower fees as well as experience with the project's type/size, the Cx firm's location relative to the project, previous successful projects, Cx training and certification, staff availability, and other considerations, should be created.
One unique indicator of Cx ability is a firm's ownership of testing equipment. If a firm is offering to perform Cx, which is mainly field verification, but has no in-house measurement and testing equipment, the district might question whether the firm is a Cx provider or simply a consultant hanging out a Cx shingle. Typical Cx-firm equipment includes electronic/digital temperature, humidity, air-velocity, and fluid-flow meters and sensors. Remote long-term and short-term data loggers are necessary for guidance during occupancy. Basic air-balance equipment allows an independent check of a test, adjust, and balance (TAB) contractor. Volt, ohm, and milliampere (VOM); grounding; power-quality; and power-factor measuring equipment diagnose electrical performance. Blower doors and in-situ/portable moisture meters test roofs and walls. (This should be done during construction, not after.)
After receiving an equipment list from a prospective Cx provider, a school district might request calibration certificates to see who really is using and maintaining the equipment.
Although selection should never be based on fees alone, the range of fees submitted should be used as an overall guide to the success of an RFP. If the range is wider than 40 percent from the highest to lowest fee, the district should consider asking some questions, leveling the assumptions, and perhaps even reissuing the RFP. A clear, concise, and considered RFP makes all of the difference.
The first rule of Cx is that the CxA must be independent of the core design and construction team. This allows unbiased judgments by the CxA as he or she checks bid documents (plans and specifications) and verifies the operation of the installed equipment. Engineers who design projects are not capable of checking plans and specifications objectively. A fresh set of eyes sees things the designer does not.
Medium- and large-size firms might be able to commission their own designs by having someone from a separate Cx group do the work. Multiple offices and partners/lines of reporting help this independence. The U.S. Green Building Council and others generally agree that acceptable unbiased judgments cannot be obtained when general contractors/subcontractors are left to confirm correct operation of systems they installed.
There are many Cx firms to choose from, and rarely is there a need to use the same firm for design, construction, and/or Cx. The Building Commissioning Association (BCA) includes a list of certified Cx professionals on its Website (http://bit.ly/cAuve0).
Some school districts issue RFPs that combine Cx with TAB. TAB consists of final piping and ductwork adjustments that ensure water and air volumes equal the levels described in plans and specifications. If TAB is not performed correctly, equipment, such as terminal units at the end of ducts and pipe runs, may be short of air and/or water and, therefore, fail to heat and cool to rated capacity. Temperature-related complaints made shortly after occupancy may be caused by insufficient TAB (and insufficient controls).
Because TAB is a critical process that occurs near the end of a project, it sometimes is combined with Cx into a single contract. Although this results in one fewer contract for the owner to administer, it is not a good idea. Just like CxAs, TAB providers have their own rules and certifying organizations. TAB should be completed first and then confirmed via sampling by the CxA.
Traditionally, TAB has been a bid service at the bottom tier of the mechanical/sheet-metal/piping hierarchy. It is better to contract TAB directly through the owner, so he or she has additional insight into the quality provided by the contractors and another chance to head off problems that otherwise may become evident only long after the facility is occupied and contractors have left the site.
Lines of communication should be described explicitly in an RFP. When it comes to Cx, the best arrangement is for the CxA to report directly to the owner or a specific delegate. The delegate does not have to be an engineer on the owner's staff: Anyone with a common-sense understanding of the construction process would be appropriate. The delegate does not need to know the technical side of HVAC, lighting, and envelope performance. It is only necessary that he or she apply common sense to the CxA's technical judgment and track the process as it proceeds. Additionally, the individual must be able to reject contractor payments when needed to attain required system corrections.
If the owner does not have a person who is qualified to track the Cx process, an owner's representative (OR) can be hired to protect the owner's interests. The OR usually is someone other than the construction manager, to avoid conflicts. The OR can appoint a person to be the Cx focal point, collect documentation, and approve payments as equipment and systems are verified.
If the construction manager does not hold any contracts and has no financial contingencies in the project, he or she can represent the owner and communicate with the CxA. Medium- and large-size school districts should consider sending someone from their project team to a Cx training course to understand the process better. Again, this person does not have to be an engineer or a technician; a common-sense understanding of construction is enough. These types of courses are offered by the BCA, the University of Wisconsin, the Association of Energy Engineers, and others. This kind of training provides valuable insight into developing an accurate RFP.
Many schools use large numbers of small HVAC equipment, such as cabinet heaters, reheat boxes, variable-air-volume (VAV) terminal units, fan-coil units, and exhaust fans. These items can be sampled to establish quality levels at a substantial savings compared with testing every single unit. Critical units should be sampled at a higher number than non-critical ones.
If no issues are found, comparable pieces of equipment likely have a similar high rate of accuracy. If errors are found, a new sample needs to be selected. If errors are found in the second sample, the entire lot should be tested.
Further, if a school only has two boilers, two chillers, two cooling towers, and six air-handling units, all of the equipment should be tested. If the school has 30 to 300 repetitive items, the equipment should be tested at a rate of 15 to 40 percent depending on criticality. More guidance on equipment sampling can be found in ASHRAE Guideline 1.1-2007, HVAC&R Technical Requirements for the Commissioning Process.
An RFP should include a table of planned equipment and sampling rates the CxA must satisfy. A difference in Cx fees of 15 percent vs. 100 percent of 300 VAV boxes is huge. An RFP also should state that repeat testing after the first retest will be billed to the installing contractor and that the CxA will be reimbursed for the extra time required on the job. This puts the cost incentive for quality squarely in the lap of the installing contractors and will level the fee programs from the prospective Cx providers.
The “deliverable” section of an RFP provides another pointed explanation of what is expected from the CxA. Typical deliverables include a review of the owner's project requirements, a Cx plan, a design-review report, Cx specifications, a deficiency database (updated weekly during functional testing), systems manuals, a final report, a training verification plan, an off-season testing plan, and a warranty walk-through report.
The Cx RFP is the first step in a successful school construction project. When an owner assumes responsibility for defining a project's Cx quality assurance, he or she takes the first step in controlling the quality of the finished building. Start Cx early and right with an accurate and thoughtful RFP, and a quality project will follow.
A commissioning project manager for AKF Group LLC, a full-service engineering firm, Ron Wilkinson, PE, LEED AP, is an authority on commissioning Leadership in Energy and Environmental Design (LEED) Green Building Rating System projects and sustainable buildings. He is the author of the first commissioning training program for LEED for New Construction and Major Renovations, the chair of the commissioning advisory committee of The American Institute of Architects (AIA) Committee on the Environment, and the recording secretary for American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) Guideline Project Committee 0.2/1.2, The Commissioning Process for Existing Building Systems and Assemblies/The Commissioning Process for Existing HVAC&R Systems. An ASHRAE Distinguished Lecturer and an AIA Continuing Education Lecturer, he has spoken on commissioning practices internationally. He is a longtime member of HPAC Engineering's Editorial Advisory Board.
The team tasked with developing request for proposals for a school project should consist of:
When commissioning (Cx) a school, several questions need to be asked. Try these for starters: