Commissioning Laboratories: Getting the Owner’s EH&S Group Involved
Commissioning laboratories is very similar to commissioning most other types of facilities.The typical motivations for commissioning, such as energy efficiency, occupant comfort and maintainability of the facility, are similar across various facility types. The significant difference when commissioning laboratories is the concern for the safety of the laboratory user and maintainer.
The additional effort required to ensure a safe laboratory requires cooperation and coordination between each of the owner, designer, builder and commissioning groups.Naturally, cooperation with the owner’s operations and maintenance staff is essential when commissioning any facility; however, because of the importance of safety, laboratory commissioning must go a step further and include the owner’s environmental health and safety (EH&S) group in the discussion.
Though individuals must assume significant personal responsibility, the owner’s EH&S group is ultimately responsible for creating and maintaining a safe laboratory environment.The EH&S staff members know the habits and capabilities of the people who use and maintain the laboratory as well as the agents and chemicals being used.They are also responsible for establishing and enforcing the standard operating procedures (SOPs) that govern laboratory use and maintenance.Both design professionals and the commissioning provider should consult EH&S in regards to the containment goals for fume hoods and bio-safety cabinets, to gain an understanding of their campus primary and secondary barrier concepts and to gain an understanding of the facility SOPs.This information is then translated into design parameters, which subsequently will be verified during the commissioning process.
The design intent contains the metrics that will be used to define and judge the laboratory; it therefore must be as comprehensive as possible and presented in verifiable terms.The integration of commissioning into the design process begins with the development of an in-depth design intent document, which describes the project goals both qualitatively and quantitatively.
Quantitative criteria used to describe the laboratory with regards to safety generally starts with:
Minimum and maximum room differential pressures
Maximum recovery time following system or equipment failure
Maximum recovery time following system intervention (i.e. fume hood sash position change)
Time limit for loss of pressurization during system or equipment failure
Allowable sensor error
Qualitative parameters for the laboratory systems include:
Space pressure reference points (a known and stable location)
Specific details surrounding‘HAND’ operation of equipment (i.e., equipment should be able to operate in a safe manner when control systems have failed.)
Primary and secondary boundaries
It is no accident that functional performance testing is synonymous with commissioning; the success of any commissioning program is primarily based on the effectiveness of the testing process.It therefore is essential that test documentation be well designed.
As a basis, the commissioning provider must consider how systems will be challenged so that the overall design will support the proposed test strategy.For example, if an air-handling unit system failure is going to be simulated by failing the breaker for a fan, then it would be undesirable for the system controller to also be served by that same power source.
In general, the design professionals and the commissioning provider should coordinate their efforts so that the functional tests challenge the systems in an incremental manner.Inevitably, as this process develops, smaller details will be discussed and the finer points of the design and test procedures will result.By the end of the design stage, the functional performance tests should be sufficiently developed so that each parameter of the design intent is challenged.The spin-off benefit will be the additional detail in the design and fully coordinated test procedures.
In addition to participation in the normal static testing of duct, piping and power distribution systems, the key to successful commissioning for laboratory safety during construction is schedule integration.
During construction, the commissioning team must be attentive in their observations so that the details defined in the project manual can be verified in real time.Milestones are identified in the schedule when key features that define laboratory boundaries and details will be complete.Then verification processes are executed.This is especially important when features will be buried by subsequent construction processes.Consideration should also be made for the operation of equipment that will support testing procedure during construction.For example, if differential pressure is required between spaces to verify sealing at laboratory boundaries before all architectural finishes are complete then a milestone for completing the exhaust air system may be established.
The commissioning provider will find that most builders are willing to integrate verification processes into the construction schedule if it means certain features will not have to be revisited in the future, especially if re-visitation requires destructive means!
A system’s ability to respond accurately and repetitiously to outside influences enables the laboratory to achieve a stable environment.These concepts are used to evaluate laboratory systems and are defined as follows:
Repeatability %%MDASSML%% The ability of a system component to consistently replicate a desired output such as pressure or airflow under varying outside influences.
Stability %%MDASSML%% The ability of a system component to maintain a desired condition/output despite varying outside stimulus.
Accuracy %%MDASSML%% the ability for the instrumentation to report correct, calibrated data while considering propagation of error due to multiple contributors of information.Accuracy can also be described from a system perspective when evaluating its ability to achieve the desired outcome (air flow, room pressurization, temperature, etc…)
Responsiveness %%MDASSML%% the ability for the system’s components to collectively react to outside stimulus while maintaining the desired conditions of the system (air flow, pressurization, temperature, etc.)
The mechanisms normally utilized to evaluate the parameters associated with these concepts are the trending features of the laboratory control and building automation systems (BAS).Prior to the functional testing process, it is beneficial to ensure that the trending capabilities of the BAS are adequate.Too often, the frequency of data point sampling available from the installed BAS is barely adequate to evaluate true system performance.If the BAS capabilities are limited to a maximum data collection frequency of about one sample per minute, then other plans should be made for monitoring data such as with stand-alone data loggers which can process data in the millisecond range and ensure that a two to five second responsiveness can be adequately tested.
Laboratory functional testing should include the participation of the design engineer, campus EH&S and facility maintenance personnel.Demonstration by the controls programmer/installer is mandatory for maximum insight into issues and to eliminate the need to reproduce failures.Incidentally, participation of the facility maintenance group during the functional testing process also leads to more effective training sessions.
In additional to verification of sequences in normal operating conditions, testing should include evaluation during failure and recovery modes, stand-by power operation and any other scenarios in which the system may be required to operate.
Effective laboratory commissioning requires more than just sound technical capabilities by each member of the project team; it also requires coordination, communication and cooperation as early in the project as feasible.
It is essential to define the facility qualitatively and quantitatively in the design intent document.Furthermore, it is necessary for the commissioning provider to work with the design engineers in order to design the functional tests to challenge the systems properly.Construction schedule integration is essential to enable review of construction details in real time.Finally, functional testing in the laboratory environment should be executed focusing on stability, accuracy, repeatability and responsiveness.After all, we all have the common goal of providing a safe and productive environment for our researchers.
For more about commissioning research and testing laboratories, check out the August issue of Consulting-Specifying Engineer.