Commissioning Building Systems for Improved Performance and Cybersecurity

Summary

People spend most of their time inside buildings, which makes providing comfortable ambient conditions an essential service. However, commercial and institutional building heating, ventilating, and air-conditioning (HVAC) systems consistently underperform relative to expectations for comfort conditioning and their performance tends to degrade over time. This loss of performance can increase lifecycle costs and degrade occupant productivity.

Building systems commissioning is a quality control process for HVAC systems. When applied at the design phase and throughout the building life cycle, it has been shown to effectively improve building performance and reduce energy waste. Despite the benefits, commissioning is underutilized because current practices are labor intensive and require considerable technical expertise. NIST will develop the measurement science needed to enable commissioning techniques that leverage the embedded capabilities of building automation and control systems to automate functional performance tests and analyze the results in ways that improve building performance and reduce costs. The results can be used by industry to improve best-practice guidelines.

Description

Objective 
To improve the performance of building systems by providing the measurement science needed to develop improved building commissioning techniques that utilize embedded capabilities of building control systems, accelerate the adoption of cost-effective commissioning as standard practice and enhance building cybersecurity.

Technical Idea
ASHRAE has published Guideline 36, High Performance Sequences of Operations for HVAC Systems. The new technical idea is to leverage these new recommended sequences of operation and NIST’s control expertise to develop and validate a library of automated commissioning tests linked to the standard sequences of operation. This validation work can become the basis for new industry guidelines or standard methods of test for building system commissioning tools. In addition, NIST will work with the National Cybersecurity Center of Excellence (NCCoE) to convene an industry community of interest to develop a community profile for cybersecurity of building systems.

Research Plan
NIST will enable the testing and verification of design sequences of operation and to identify mechanical equipment faults, cybersecurity deficiencies.  Research efforts will focus on measurement science needs identified by the industry.  Functional performance tests for the ASHRAE Guideline 36 sequence of operations will be developed and implemented in the HVAC-Cx tool.  The Virtual Cybernetic Building Testbed (VCBT) will be configured to represent a variety of HVAC system designs appropriate for applying the Guideline 36 sequence of operation.  Using the VCBT as a laboratory test building, automated commission tests will be developed and evaluated under normal conditions and with a variety of common HVAC system faults. Field trials will also be conducted with a local building commissioning firm and a local college to confirm laboratory results and evaluate the usability of the tools.

The NIST Engineering Laboratory will work with industry throughout the development process to establish technology transfer of our research products. Research results will be disseminated to a wider audience through informative journal publications, involvement in the development of key industry guidelines (ASHRAE Guideline 36 - High Performance Sequences of Operation for HVAC Systems, ASHRAE Guideline 1.2 Commissioning Process for Existing HVAC&R Systems) and educational activities such as webinars and tool demonstrations.  Steps will also be taken to make NIST-developed tools and the guidance for using them publicly-available online.

Major Accomplishments

Outcome

• HVAC-Cx automated commissioning tool for AHUs, chillers, and VAV boxes
• Functional Performance Test Module component of HVAC-Cx updated to work with industry partners
• CITE-AHU tool for automated commissioning of air-handling units
• Completed IEA Annex 40, Commissioning of Building HVAC Systems for Improving Energy Performance and IEA Annex 47, Cost Effective Commissioning for Existing and Low Energy Buildings.

Potential Impact

• HVAC-Cx automated commissioning tool for AHUs, chillers, and VAV boxes
• FPTM tool for validating Guideline 36 compliant test scripts and control sequences