Last month, this column acknowledged the fact that some projects do not have written Owner’s Project Requirements (OPR) documents for the commissioning professional to reference. An OPR is intended to articulate the owner’s acceptance criteria for the systems to be commissioned. It is the performance for which the design team should size, configure, and control the new systems, and it is the performance against which the commissioning professional should test the systems.
Criteria included in an OPR can include anything the building owner values, but the following is a limited list of common parameters. To be meaningful, each of the OPR parameters needs to be defined in measurable and verifiable terms.
- Outdoor air design conditions for winter and summer (temperature and moisture)
- Indoor air design conditions for winter and summer (temperature and moisture)
- Morning warmup maximum recovery time
- Indoor air quality (CO2 concentration, PM2.5, VOCs, outside airflow rates, etc.)
- Overall building pressurization
- Interior space pressure relationships
- Minimum or maximum airflows (air changes per hour, cfm per square foot, etc.)
- Domestic hot water supply temperature
- Domestic hot water maximum delivery time
- Indoor light levels
- Equipment and outlets served by emergency power
This month, I will explore options for commissioning professionals when neither the owner nor the design team is forthcoming with objective acceptance criteria for the commissioned systems. This starts with the commissioning design review. Without an agreed-upon OPR, what objective criteria can the commissioning professional reference when evaluating elements of the design team’s work? The concept of, “It just doesn’t seem right,” will not be very compelling.
Codes. Applicable code requirements are a solid resource for that performance criteria. However, the thing to remember is these are “minimum” requirements and the owner may need/want better than that.
It is not typically in the commissioning professional’s contracted scope of services to perform a thorough code-based review, i.e., reviewing the design against all applicable code requirements. However, if the design appears suspect, the commissioning professional may find code-based criteria against which to support that suspicion.
Industry standards and guidelines. Many building system-oriented industry groups and building usage-oriented owner groups have published guidelines that refine performance criteria for specific applications. The following are just a few examples:
- ASHRAE standards and guidelines
- NFPA standards
- IES standards
- ISO standards
- EPA guidelines
- NIBS guidelines
- FDA Current Good Manufacturing Practices
- OSHA laws and regulations
- FGI Guidelines for Hospitals and Outpatient Facilities
- ILAR Guide for the Care and Use of Laboratory Animals
- ASPE Plumbing Design Guidelines
As with the codes, these guidelines and standards can be used by the commissioning professional to cite commonly accepted criteria to support design review comments. However, it is not the commissioning professional’s responsibility to confirm that the design is compliant with all industry standards and guidelines.
Past experience. One of the most powerful things a seasoned full-time commissioning professional can bring to a project team is experience on scores (if not hundreds) of projects — often more projects per year of professional experience than design engineers. As such, they have seen more systems, more control sequences, and more operational approaches that do or do not work. Commissioning professionals often have far more field experience with dynamic building systems than design engineers. These real-life past project experiences, lessons learned, and best practices can help a current project avoid similar pitfalls and benefit from previous projects’ learning curves.