4. Preparing for System Integration Testing

Planning and preparation is crucial for functional testing success, especially at the system-integration level. Planning and preparation requirements fall into three general categories:

·       Testing Hierarchy Initiating a test at a system level when the components are not ready can be frustrating at best and disastrous in some cases. The testing plan must be structured in a manner that builds from the simple to the complex and from the utility systems to the end-user systems.

·       Climate Interactions By nature, buildings and their systems are designed to create a controlled environment, isolated from the local climate. To do this, the systems need to function over the entire range of conditions that will be encountered, and a major goal of integrated operation testing is to verify that contingency. Thus, the testing plan must consider the juxtaposition of the commissioning and start-up schedule with the seasons to anticipate and plan for deferred testing where necessary and to protect the building and untested equipment that is coming on line from damage due to inappropriate operation for the current climate conditions.

·       Operating Environment Compressed schedules and phased occupancy are becoming the rule in modern construction. These contingencies frequently force phased start-ups of partially complete systems to serve portions of a building that will become occupied and fully operational before the fabrication of the system is complete. In addition, the need for a semi-controlled environment to facilitate the installation of finishes can create intense pressure to use the partially complete HVAC systems for temporary heating and cooling, a high-risk undertaking in many circumstances. Retrocommissioning projects, by nature, are challenged with testing machinery that is serving an operating facility with out disrupting operations. Thus, it is essential that the test plan take these issues into account and include contingencies for dealing with them.

Consider these categories in relationship with each other. For instance, the Student Center AHU1 is coming on line during the summer months. Strict adherence to the testing hierarchy would dictate that the preheat coil subassembly be completely tested prior to any effort to test the integrated performance of the air handling system. However, reviewing climate data (see Figure 6) quickly reveals that it is highly unlikely that a preheat load will exist any time during the start-up window. Thus, it will be possible to verify functionality - that the coil heats the air and that the actuator strokes correctly - but it will be impossible to test the response of the coil and its integration with other control process when it is challenged with subfreezing air. This will leave a few important questions unanswered as the renovated portion of the building is occupied:

·       Will the control loop be stable during moderate weather at the low flow rates that occur when only the museum is in operation, in addition to being stable on a winter design day with all zones in operation?

·       Will the control loop respond fast enough to prevent a freezestat trip at start-up in mild and extreme weather?

·       Do the coil capacity and performance appear to be as specified?

·       Is the control algorithm set up and tuned so that preheat is not used until the system is operating on minimum outdoor air?

·       Does the preheat coil maintain the mixed air plenum at 40°F when AHU1 is not in operation?

All of these questions lead to operational issues. The bottom line is that the coil will not have been tested under actual load when the area served by the system is occupied. If the answer to any or all of the unanswered questions posed above is “No” when the cold weather finally arrives, then the outfall could be nuisance problems for the operators and discomfort for the occupants, at a minimum, and possibly a frozen coil or other damage, if there were major issues that were not detected by the warm weather testing.

After taking all of this into consideration, the commissioning provider for the Student Center project scheduled some focused testing for the coil to occur in late October. As can be seen from Figure 6, it is likely that there will be cool temperatures during the morning and evening hours, which would allow the coil to be challenged with an actual load during that time period. At the same time, it is early enough in the heating season that it is unlikely that the temperatures will dip below freezing, the condition where the real danger in terms of equipment damage exists. The provider also made a point of including the operators during the preheat coil tests that occurred during start-up to ensure they were familiar with its intended function. Finally, the provider included some focused training regarding the preheat coil’s operation and potential cold-weather problems in the training plan. These steps helped prepare operators for potential problems arising from colder-than-normal weather prior to the fall test window.

The next section looks at each of the categories outlined above in more detail: testing hierarchy, climate interactions, and operating environment.

4.1. Testing Hierarchy

Figure 4 illustrates a typical testing hierarchy for a large project.[8] This section will describe important issues related to the testing hierarchy shown in the figure.

Figure 4: A typical testing hierarchy

The functions in the box highlighted in gold could have this entire testing hierarchy associated with it.

Click figure to display it as a PDF.

1   Each of the utility systems could have a similar testing hierarchy.

The systems providing utilities such as chilled water and hot water to serve end-use equipment are typically complex. In the case of the Student Center, the central plant is an existing system that has been extended to serve a new load. Thus, in the case of our example, the complexity associated with bringing the utility on-line is minimized, but not eliminated. The following items should still be considered:

·       The new pumps and their associated secondary connections, as well as the steam pressure and condensate connections, will need to be commissioned. Functional chilled and hot water pumps and secondary control valves are a prerequisite for component-level testing of the AHU1 preheat coil, reheat coils and chilled water coil. Similarly, steam pressure and a suitable condensate-return system are a prerequisite for the operation of the trim humidifier and some of the new kitchen and domestic water heating equipment associated with the renovation project.

·       The central plant needs to provide chilled and hot water to meet the design specifications. This seems obvious, but it often is overlooked. Additionally, the plant-operating characteristics could have been improperly communicated to the design team, resulting in the new equipment being mismatched to the current plant-operating strategy. The result can be bad feelings on the part of the plant-operating staff, who must now re-tune their plant to operate for the benefit of one new load. Or, worse yet, it can mean that the design intent of the project will not be met if the plant is simply not capable of performing as anticipated by the designer. In any case, it is beneficial to review the new system-operating requirements with the central plant’s operating staff early in the design process.

·       Reliable mechanical systems require reliable electrical systems: Motors will not operate without electricity. Prior to starting motor-driven equipment, the testing activities associated with the electrical system need to occur. While it may be possible to postpone some electrical testing activities without endangering lives or equipment, commissioning at a later date will likely result in an interruption of service, which the owner and construction team will have less tolerance for as the completion date approaches.

For the Student Center, a reliable electrical system translates to testing the normal power system well in advance of mechanical equipment start-up. Testing the emergency power system can occur in parallel with the early stages of mechanical system testing, but must be complete before testing the integrated response to a power outage and subsequent transfer to emergency power. Such a test is not a requirement for an occupancy permit at the Student Center. Instead, it is driven by the owner’s requirements for the museum and administration offices. However, for mission-critical facilities such as hospitals and some process plants, integrated testing of the building’s response to a power failure and transfer to emergency power may be on the critical path to an occupancy permit. All of these factors need to be taken into consideration as the project test plan is developed.

2   Many of the early test processes leading to integrated testing can occur concurrently.

As can be seen from Figure 4, during the early stages of functional testing it is possible to have multiple tests occurring in parallel in cases without the dependency by one test or verification sequence on the performance or readiness of the others. Utility systems can be in the final stages of integrated-system testing while the controls and components of the systems they serve are being verified and tested. Similarly, components with a contractual or warranty requirement for a factory start-up can have factory tests performed concurrently with component-level tests in other areas of the system.

For the Student Center project:

·       AHU1 control-connection checks and calibration checks can occur while integrated testing is in progress for the chilled water pumps, hot water pumps, steam piping, and electrical-power system.

·       The factory start-up of the variable speed drives can occur as soon as the power and control systems are ready.

·       Verification checks and limited testing of coils and terminal units can begin as soon as the power, water, and control systems associated with them are available.

3   The start-up process - building from the simple to the complex – starts with verification checks.

Figure 4 shows that less complicated functions and verifications are generally prerequisites for verification of more-complex functions and processes. Verification checks, such as pre-start checks, are typically static inspections and fall into the following categories:

·       Best practice issues, such as drive alignment, belt tension, and the security of motor connections.

·       Control system issues, including sensor location, point-to-point verification, and calibration.

·       Implementation issues, including the proper configuration of piping and duct connections.

·       Operations and maintenance issues, such as the confirmation that access doors will fully open and that service valves isolate the coils they serve and provide clearance for coil removal.

By nature, static checks will be easier to accomplish than dynamic checks. For example, inspections can verify the piping configuration of the pumped preheat coil associated with AHU1 is correct, the necessary sensors and valves have been installed and properly located, and the coil is in the proper location in the air handling system. Ensuring that everything is in the correct static configuration paves the way for making sure that small collections of parts can work together without causing problems (which is component-level testing).

4   Component-level testing is the first step beyond static inspections and tests.

Returning to the Student Center AHU1 preheat coil example, logical next steps for testing its components include:

·       Verifying pump operation and rotation.

·       Verifying the coil is receiving water at the correct temperature and flow rate from the central plant.

·       Verifying the control valve does not leak when commanded to fully close.

·       Verifying the valve and pump can be controlled and monitored by the DDC system.

All of these tests move beyond static inspections by verifying a simple, dynamic function or process. Once they are completed, the entire preheat coil subassembly, which is a component of the AHU1 system, can be tested to verify the functionality of the control process for the preheat coil discharge temperature.

5   Integrating components into working sub-assemblies paves the way for system-level testing and integration.

Continuing with the AHU1 example, one of the goals associated with functionally testing its discharge-temperature control system is to address the complex interactions illustrated in Figure 1. The successful integration of the preheat coil with the chilled water coil and economizer dampers ensures that:

·       Preheat will only occur when the economizer cycle (a cooling process) is at the minimum outdoor air position (a limit set by the building’s ventilation requirements).

·       Chilled water will only be used if the free cooling provided by the economizer cannot deliver the desired discharge temperature.

·       The free-cooling function represented by the economizer process will be terminated when it no longer is beneficial.

·       The relatively rapid response of the economizer to a demand for cooling when the system starts up on a cool day will not result in start-up difficulties, such as nuisance freezestat trips.

6   Once the components have been integrated, the interactions of the systems with each other and the building envelope can be tested and tuned.

Typically, testing at this level is targeted at addressing a number of operational concerns, including the following questions.

1   How will the utility systems respond to the sudden load change associated with a scheduled system or building start-up?

2   Are the control sequences and interlocks properly coordinated to prevent problems when a power outage occurs and emergency power systems start and return some, but not all, of the systems to service?

3   Will life-safety functions (such as a fire alarm or a smoke-management cycle) trigger problems in the mechanical systems as operating modes change and fire and smoke dampers rapidly reposition when triggered?

4   How do the HVAC systems respond to the sudden and significant flow and pressure changes that occur when the economizer transitions from 100% outdoor air to minimum outdoor air when the outdoor conditions make using outdoor air undesirable?

5   Do the HVAC systems appear to be capable of maintaining the desired indoor conditions during extreme weather?

6   How do the HVAC systems, utility systems, and building environment and envelope respond to start-ups during extreme weather?

7   Are the warm-up and cool-down set points proposed by the control sequence appropriate for the building’s thermal characteristics, occupancy pattern and the ambient environment?

8   Are the systems tuned and stable under all of variable operating conditions created by occupancy patterns and daily and seasonal environmental changes?

Active Testing

The first four questions above can be answered using active, manually triggered testing strategies. Active testing is appropriate for issues that have three characteristics:

·       The questions they pose can be answered by initiating the triggering event, observing the response, and correcting any deficiencies.

·       The triggering events are large, rapid step changes in operating mode rather than long-term, gradual changes.

·       The issues are fairly independent of the ambient environment and building occupancy.

Passive Testing – Trending and Datalogging

In contrast, the last four questions lend themselves to passive testing using trending and data logging techniques and seasonal testing. Generally, passive testing is appropriate in the following situations:

·       To observe the building’s response to real-time stimuli and verify the solutions that are implemented. The real-time response of a building to the environment and its occupancy patterns can be virtually impossible to simulate in tests.

·       To observe the response of the system to extremes in the environment that cannot be realistically simulated by manual techniques.

On first examination, the capacity test alluded to by the fifth question could be actively tested. For example, if the btu/hr capacity of the preheat coil in Student Center AHU1 was equal to or greater than the btu/hr rating of the cooling coil, it would seem as if the preheat coil could be used to perform a capacity test on the cooling coil, thus verifying the ability of AHU1 to meet the load on a design day. While this may be true on a strict btu/hr basis, there are two key issues that this approach would not address, making the results of such a test marginally useful at best in real-world operating scenario.

First, the load on the cooling coil on a design cooling day has a latent component in addition to a sensible component. Because the preheat coil can only generate a sensible load, using it to fully load the cooling coil, while numerically correct, would not reflect a true test of the cooling coil’s performance on a design day in the summer.

Second, the system’s ability to handle full load is related to – but not necessarily the same as – the ability of the heat-transfer elements to deliver their rated capacity. To address a design load, AHU1 must deliver the capacity represented by its heating and cooling elements to the location where the load exists in harmony with the requirements of the occupants, the dynamics of its distribution system, the dynamics of the building’s thermal and leakage characteristics. All of these issues have components that have nothing to do with the capacity of the heat transfer elements. They are also virtually impossible to simulate.

4.2. Climate Interactions

The local climate can have a major impact on testing targeted at integrated operation and control on two fronts:

The building and its systems are intended to isolate the occupants and building functions from the impact of the local climate.

The degree of isolation required will vary with the location and the requirements of the building occupants. For example, a properly oriented and sized thatched roof is all that is necessary for sipping wine while watching a sunset on the coast of Kauai, Hawaii. In contrast, a hospital in Nome, Alaska would require significantly more attention to the envelope design as well as to the systems serving it. Understanding the environment and the demands it will place on the building and its systems are key considerations for everyone involved with its design, construction, and operation.

Local climate conditions will impact the testing schedule.

During the later phases of integrated operation testing, this represents an opportunity to verify performance under real-world operating conditions. But during the early stages, it can represent a challenge because the systems must be operated to accommodate the start-up and testing process, but may not be ready to address some of the challenges the local climate has to offer.

Figure 5 illustrates the annual climate patterns at a number of locations in the United States. The data were obtained from the National Climate Center and represent information collected by their Automate Surface Observation System (ASOS) network. Sidebar 2: Obtaining Hourly Climate Data contains information about how to gather and use this data. Figure 6 is an enlarged view of the data for St. Louis International Airport, which happens to be adjacent to the campus on which the Student Center is located. The axes on all of the figures have identical scaling factors, thus the shape of the curves can be directly contrasted.

Figure 5: Annual climate patterns at different locations in the United States

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Figure 6: The local climate at the Student Center

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Virtually every airport of any significant size has these automated observing stations, which log hourly data on the local climate, including temperature, dew point, relative humidity, wind speed and direction, cloud cover, and precipitation. For a nominal fee, the National Climate Center will provide this data to interested parties in a delimited format that can be imported into a spreadsheet program such as Excel. The graphs included in this chapter were created in this manner. The Western Regional Climate Center (http://www.wrh.noaa.gov, 775-674-7010) is one point of contact for obtaining this data. Data for the past two to four days can be found on line by visiting www.faa.gov/asos/map/map.htm and then clicking on the state and ASOS site of interest. Data can be copied and placed into a spreadsheet program via a number of techniques. For additional information on working with ASOS data refer to “Visualizing BAS Data,” by David Sellers, PE, in the September 2003 issue of Heating/Piping/Air Conditioning Engineering magazine.

Three different data streams are presented in each graph. Dry bulb temperature and relative humidity values are from the ASOS sites. This information, along with other ASOS data, were used to calculate enthalpy by making a simplifying assumption and then applying the equations found in Sidebar 3: How to Calculate Enthalpy.

Enthalpy is important because it makes a statement about the total energy content of the air, not just the sensible energy we feel as dry-bulb temperature or the latent (moisture) energy we commonly associate with relative humidity.

Lines have also been plotted that correspond to the following conditions:

·       0.4% and 2.0% Cooling Design Conditions and 99.0% and 99.6% Heating Design Conditions: These values were taken from Chapter 27 of the ASHRAE Handbook of Fundamentals (2001 edition) and represent common design targets for many HVAC processes and buildings.

·       75°F: This is a very common design temperature for spaces in commercial environments and is at the center of the ASHRAE Comfort Envelope.[9]

·       Enthalpy Corresponding to 78°F and 45% RH: This is about what the return air enthalpy would be from a “typical” 75°F space with a design relative humidity of 50% after gains in a ceiling-return plenum or duct system are taken into account. It approximates the change-over setting for an integrated economizer equipped with an enthalpy-based change-over that serves a typical space. If the outdoor air enthalpy is below this value, an integrated economizer cycle will use less energy by remaining in the 100%-outdoor air position, rather than recirculating with minimum outdoor air.

·       32°F: This is the temperature at which liquid water becomes ice. If the water happens to be in a coil, there can be a big problem. Climates that experience temperatures at or below freezing expand the range of possible outcomes for deficiencies in the testing and operation of HVAC systems and buildings compared to climates that do not experience freezing weather. These additional issues included energy waste, nuisance shutdowns, and freezing and water damage.

To calculate enthalpy, a simplifying assumption is made, followed by a series of calculations.

By definition, the degree of saturation (µ) of air can be calculated using Equation 12 from Chapter 6 of the ASHRAE Handbook of Fundamentals, 2001, which is outlined below.

However, the degree of saturation and relative humidity are approximately the same at temperatures below 100°F. This simplifying assumption is then applied to the previous equation by substituting relative humidity form, obtaining values for Ws from a psychometrics chart and calculating W. Rewriting the equation above, we get:

W = %RH x Ws

Where:

W = specific humidity (lbwater / lbdry air)

%RH = relative humidity of the air

Ws = specific humidity at saturation (lbwater / lbdry air)

Finally, enthalpy is calculated using Equation 32 from Chapter 6 of the 2001 ASHRAE Handbook of Fundamentals.

H = (0.24 x T) + [W x (1061 + 0.444 x T)]

Where:

H = enthalpy (Btu/lb)

T = dry-bulb temperature (°F)

W = specific humidity (lbwater / lbdry air)

Generally, with some study, the information in the figures speaks for itself. Note the following items with regard to this data and these figures.

1   The daily and seasonal range varies significantly from location to location.

Buildings that see large daily or seasonal ranges, such as Buffalo and St. Louis, will generally have more issues to deal with from a testing and operations standpoint than buildings in locations such as San Diego and Key West, Florida. Such systems need to deal with a wider range of operating conditions, and the testing process may require more re-testing to verify the correction of problems. Seasonal testing might also have to occur to allow a full assessment of performance to be made. Contingencies for weather (i.e., forecasted for the next week or so) and seasonal (i.e., predictable over the next few weeks or months) influences need to be considered when developing a testing plan. They were among the drivers behind the plan to perform focused seasonal testing of the Student Center’s preheat coil, as mentioned at the beginning of this section.

2   The nature of the anticipated problems will vary from location to location.

Annual climate summaries provide a good way to anticipate where problems may be encountered during building testing and operation. Buildings that see a lot of subfreezing weather are more likely to have problems with their freezestats and mixed air low-limit cycles as compared to buildings locations where freeze-protection features are not required. Freezing is one type of issue to be aware of, and moisture is another. For example, high relative humidity in locations such as Key West may make economizer change-over and envelope leakage much more significant than they would be in San Diego, where the conditions are such that an integrated economizer cycle will operate on 100% outdoor air for much of the time. This can be anticipated by comparing enthalpy lines for Key West and San Diego. For the Student Center, the high relative humidity experienced during a St. Louis summer makes the economizer change-over an important target. The subfreezing hours encountered in the St. Louis winter will focus attention on freezestat and mixing issues, even if the provider does not plan to do so up front.

3   Relative humidity is a relative term.

Relative humidity is by definition a relative term. In simple terms, it’s a measure of how much water is held in the air at its current temperature relative to what it could hold at that same temperature if it were saturated. For the Student Center, remaining on 100% outdoor air on a rainy, 59°F day will use less energy than shifting to recirculation with minimum outdoor air, even though the outdoor air humidity is 100%. This is depicted in Figure 7. However, the same would not be true on a rainy, 80°F day.

Figure 7: Outdoor air enthalpy on a rainy day vs. the return air from a typical space

Click figure to display it as a PDF.

4   There are significantly more hours at non-design conditions than at design conditions

Systems spend the vast majority of operating hours at non-design conditions. In fact, as can be seen from the weather graphs, there are some years where one or more of the design conditions does not even occur. The Portland data set is a good example. For the year depicted, the area never saw the 99% heating-design condition and barely saw the 99.6% heating-design condition.

It is important to remember that while the vast majority of the non-design hours will be at less than design conditions, some of them will also be at conditions that exceed design. The Portland data set also exhibits this characteristic. The same year during which the heating design temperatures were barely touched, the 0.4% cooling-design condition was exceeded significantly on several occasions. If the systems are well tuned and operated, deviations of this type may go undetected or only result in minor comfort problems for occupancies such as those of the Student Center. But for a mission-critical site, such as a clean room or hospital, loss of control under these conditions could be catastrophic.

From a functional testing standpoint, there are two factors that need to be considered in this regard.

·       For mission critical facilities, the design conditions may be the climate extremes, not the percentage of worst-case conditions that is typically used. Thus, acceptance criteria may be more stringent than normal and the need to test under the actual or near-actual conditions may be more critical.

·       Tests that place systems in non-standard operating modes on or near design days may not be possible on those days. For example, a building pressurization test uses the building’s HVAC equipment to pressurize the building with 100% outdoor air to assess leakage.

If the Student Center commissioning provider scheduled this test for early August and the day happened to be one of the hot and humid days that occurred in that month, rather than one of the mild days (see August in Figure 8), then it may become necessary to reschedule the test. This is because the air handling unit’s cooling coil was not selected to cool and dehumidify 100% outdoor air. Attempting to do so could subject the building and its contents (especially the museum) to damage from the introduction of air with a dew point above the surface temperature of the duct system.

Figure 8: Month-to-month variations in the climate at the Student Center

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5   Seasonal weather isn’t always seasonal

Despite the general regularity of weather patterns, there are always some non-seasonal days that occur (see Figure 9). Murphy’s law states that abnormal weather will occur when it is least desirable. Such was nearly the case for the Student Center project, when a partial chilled water outage was scheduled for early January to allow the replacement of the AHU1 chilled water coil.[10] Typically, January is one of the coldest months of the year in that location, so scheduling the outage to occur then seemed like a safe bet. Fortunately, the commissioning provider was monitoring the online weather forecasts and called the contractor the day before the scheduled outage and suggested waiting a week. The contractor, having been burned before, agreed. He was glad that he did because a week that had been running with highs between 40°F and 50°F suddenly had a day that nearly hit 70°F (see January in Figure 8).

Figure 9: Day-to-day climate variations at the Student Center

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Many of the points made in the preceding discussion of climate interactions may seem obvious. However, it is quite easy to acclimate our thinking to the seasonal pattern of the climate wherein we reside or do most of our work.[11] Thus, we can be caught off-guard when a new opportunity takes us to a different location or unseasonable weather strikes at an in-opportune time.

The bottom line is that climate and weather play significant roles in the integrated testing and on-going operation of a building. Taking the time to understand the climate associated with a project will facilitate the planning and execution of functional testing and provide a foundation for diagnosing and correcting problems as they occur. Keeping an eye on the weather forecast while testing and operating a building can help prevent an unexpected event from disrupting the testing process, causing a loss of control of the building environment, or damaging equipment.

4.3. Operating Environment

Bringing all of a building’s systems online in the orderly manner, as depicted in Figure 4, is probably more of the exception rather than the rule. Requirements for temporary operation and the need to obtain occupancy permits prior to formal occupancy (to allow equipment and furniture to be moved into the facility and installed) are common sources of pressure on new construction projects. Renovation projects, expansion projects, and retrocommissioning offer unique challenges because work needs to occur with minimal disruption to operating facilities. Failure to understand and address the impacts of a system test on an existing facility and its utility systems can be embarrassing and even disastrous.

From a testing standpoint, phased start-ups, out-of-sequence start-ups, and temporary equipment operation pose a number of issues, such as:

1   Out of sequence or incomplete testing can place systems at risk.

It is not uncommon for a contractor to seek permission to use the partially completed HVAC systems on a project as a source of temporary heating or cooling. Unfortunately, if this or other out-of-sequence start-ups are not handled correctly, the systems end up being abused and their long-term health is put at risk. A discussion relating to temporary operation located in the Functional Testing Basics section outlines some of the temporary operation issues from a design and testing perspective. The integrated-operation and O&M perspective that a commissioning provider can bring to a project can often be a powerful force for advocating an informed approach to temporary operation, improving the project quality while making their own job easier.

When faced with the prospect of temporary operation of AHU1 to facilitate the installation of the finishes in the Student Center, the commissioning provider responded by providing an informal list of potential pitfalls and recommendations for avoiding them. Much of the information was taken directly from past experience, supplemented with the information on temporary operation, warranties, system readiness, factory start-ups, and verification checks contained in Functional Testing Basics section. Although the contractor elected to proceed as planned,[12] he recognized that the report allowed him to make a more informed decision regarding the risk management associated with temporary operation. The provider benefited both directly and indirectly by having his concerns acknowledged and documented and generating the long-term benefits associated with the team building.

2   Out of sequence or incomplete testing can add to the time required to complete a project without changing its scope.

It might not be possible to fully test equipment placed in operation while in a state of partial completion. The provider will likely have to start and stop a test sequence, which will inevitably result in the need to duplicate efforts when the test is reinitiated because the results of the complete test will be unreliable. Having partial-test contingencies planned before they are needed allows the provider to proactively address them, thus maintaining the integrity of the commissioning process, meeting the needs of the client, and maintaining their own financial viability.

3   Many O&M problems are a result of unresolved commissioning findings.

Verification and assessment of accessibility and serviceability may seem like passive inspection functions. The reality is that, in many instances, they are active functional tests of the ongoing maintainability and operability of the equipment and systems associated with the project. They also are measures of the potential for persistence of the benefits of commissioning. Time spent during the design and construction phases of a project to assess the integrated assembly of the systems for operability and maintainability is time well spent, as can be seen in Figure 10. These efforts can yield benefits that are just as tangible as the benefits associated with functional testing for integrated operation. And the efforts yield the added benefit of paving the way for a smoother start-up and testing process.

Figure 10: Issues identified during the construction observation process at the Student Center.

Generally, it should not be necessary to remove a wall to gain access for fire damper inspection and maintenance (left). Most fire and smoke dampers require access for more than just inspection; planning to access the components on the far side of the duct through an 8-in. x 12-in. opening 36-in. away is probably not realistic (right).

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All of these factors came into play on many fronts for the Student Center. One example is the commissioning process associated with the fire and smoke dampers. As described previously in Sidebar 1: Design Phase Commissioning – A Foundation for All That Follows, early commissioning involvement can lead to ongoing operational savings by reducing the pressure drop associated with the normally open fire/smoke dampers. Subsequently, the provider focused some effort at ensuring the dampers were installed in a truly accessible manner. Several issues were identified and resolved in a timely manner, some of which are illustrated in Figure 10. These design and construction phase efforts paved the way for a smoother final inspection and functional test. The final inspection and test ensured that the damper could be inspected and maintained, avoiding citations and associated fines when the local building inspector inevitably asks for proof of compliance with NFPA 90A in the years to come.

4.4. Planning Tools

There are a number of tools that the commissioning provider can use to their benefit while planning the testing process.

1   The commissioning plan and testing plan

The commissioning plan, and the testing plan that is integral to it, are two of the most powerful tools available to the commissioning provider. These documents allow the process to be organized from the start and modified as the requirements of the project evolve. The commissioning plan typically identifies what components, subassemblies, and systems are to be tested, the roles and responsibilities of each member of the commissioning team, and a general schedule of when various commissioning activities will occur. The testing plan not only provides more detail about actual test procedures and the testing schedule, but also outlines weather and seasonal contingencies.

2   Commissioning meetings

Properly managed (i.e., brief and non-confrontational), commissioning meetings can be powerful avenues for communication between the project team members. Clear, unrestricted communications is an integral part of any successful commissioning process.

3   Gantt charts

“A picture is worth a thousand words” and Gantt charts can provide a picture of the functional testing process and all of the interactions they comprise. If the provider develops their plan using a software package compatible with the construction manager’s, the testing plan can be easily merged with the overall project plan, thus multiplying the benefits of both.