ET24SWE0019 - Automated Guideline 36 Validation

This proposed CalNEXT project will develop a test method to validate that control programming is consistent with the control sequences in ASHRAE Guideline 36 (G36) High-Performance Sequences of Operation for HVAC Systems. The eventual goal is for the test method to evolve into an ASHRAE standard and become the basis of a Title 24 certification requirement. A working group has been established to begin collaborating on G36 testing procedures with several building automation systems (BAS) manufacturers directly involved.

Poorly implemented BAS is widely recognized as a major cause for HVAC systems that fail to meet their design intent, not maintaining thermal comfort and resulting in poor energy performance. Challenges stem from a variety of factors including lack of controls understanding by designers, poor workmanship by installers, and inadequate commissioning processes. G36 was developed to address these issues.

G36 provides high-performance sequences of operation, which are English-language descriptions for how HVAC systems are controlled by building automation systems. The use of G36 sequences provides significant energy efficiency and indoor environmental quality benefits compared to standard practice. Moreover, industry standardization around G36 provides the potential for substantial streamlining and improvement in implementation quality by allowing the G36 logic to be programmed and tested centrally by the major BAS manufacturers. Rather than the current approach of having individual installers interpret and program the control logic on a project-by-project basis, a process that is labor-intensive and vulnerable to quality control issues, installers could instead draw from pre-programmed logic from within a library of manufacturer programming.

BAS manufacturers have begun to program G36 centrally and some have released templates of G36 control logic in their unique programming languages for use by their installers, but these G36 programming libraries are not yet widely used. Objective testing is needed to spur the use of these pre-programmed libraries of control logic, to provide assurance that the libraries are robust and consistent with G36, and to realize the full potential of industry standardization around G36. The method of tests developed as part of this effort would help fulfill market demand for clarity on how to interpret G36 and an objective basis for confirming completeness and quality. In addition, the California Energy Commission is evaluating a draft change to the 2025 version of the California Building Energy Efficiency Standards (Title 24) to require the use of a certified G36 programming library. If adopted, this method of test could support future versions of the code to provide robust programming validation and become the future basis of the Title 24 certification requirement. The bulk of the work of this effort is to develop the detailed procedures for evaluating each sequence within G36, and to conduct outreach to ensure broad stakeholder support, particularly among BAS manufacturers.

Field demonstrations of G36 have shown significant energy savings over current practice and tools to enhance and streamline the use of G36 are needed to accelerate awareness and adoption of this emerging technology.

The primary deliverable of this project is a test standard for an automated approach to validate G36 programming. The test standard is intended to eventually be developed into an ASHRAE standard and become the basis for a newly proposed Title 24 requirement for the use of a certified G36 library in a future code cycle.

Building automation systems frequently underperform due to inconsistent control implementation, gaps in commissioning, and project‑specific reprogramming that “reinvents the wheel.” American Society of Heating, Refrigeration, and Air-Conditioning Engineers (ASHRAE) Guideline 36 (G36) offers standardized, high‑performance sequences of operation that can improve comfort, indoor air quality, and energy efficiency. Major building automation system manufacturers have also begun to release G36 programming libraries. However, in the absence of an objective, vendor‑agnostic test standard, users cannot reliably assess their conformance, completeness, or robustness. Early field experience has shown inconsistencies and incomplete implementations, illustrating the need for a rigorous and repeatable validation method. 

This project developed a draft method of test and demonstrated an automated, repeatable bench‑scale validation approach to confirm that control programming conforms to G36 sequences of operation, thereby enabling scalable quality control, supporting codes and standards, and reducing deployment risk. The method uses a software testbed connected to a physical building automation system controller to apply scripted operating conditions and compare the controller’s outputs to expected results. The approach provides objective, vendor‑neutral validation that can be performed by programming developers as well as independent testing organizations.

Key accomplishments include:

• Test architecture and scripts: Developed a modular test structure based on discrete test steps and test blocks, enabling detailed evaluation of controller responses across a range of G36 airside sequences. Machine-readable test input files include a point mapping index for a Building Automation and Control Network point translation, test script files providing detailed test conditions and expected responses, and a configuration file defining test selection and reporting intervals.
• Software tool enhancements: Collaborated with two federally funded research teams to develop software tools capable of implementing the new test procedures. 
• Pilot testing: Conducted iterative pilot testing with a building automation system manufacturer's G36 variable air volume reheat program and with an open-source G36 programming implementation. These pilots confirmed the feasibility of automated conformance testing and informed refinements to the test scripts, point naming, and software requirements.
• Industry and standards engagement: Worked closely with building automation system manufacturers, ASHRAE G36 committee members, and California Title 24 stakeholders. The project team successfully proposed and formed ASHRAE SPC 236, a new standard committee dedicated to developing this method of test into an American National Standards Institute standard.
•  

A standardized method of test will:

• Provide clear, objective criteria for evaluating G36 conformance.
• Improve quality and consistency of manufacturer programming libraries.
• Reduce the need for project‑specific programming and troubleshooting.
• Support codes and standards, including future Title 24 cycles.
• Strengthen the foundation for utility programs seeking to promote advanced controls.

By validating control programming at the library level, the method of test enables scalable quality assurance before installation, reducing downstream commissioning burdens and improving long‑term system performance.

To advance toward publication of ASHRAE Standard 236 and support broader market adoption, the following actions are recommended:

2. Continue refining test scripts and definitions through the Standard 236 project committee, prioritizing core G36 airside sequences.
3. Expand pilot testing to additional manufacturers’ programming libraries to address architecture and point‑exposure variations.
4. Secure dedicated funding for ongoing method of test development, which requires deep technical expertise and familiarity with G36.

5. Coordinate with California state codes (Title 24) and utility programs to establish pathways for integrating validated G36 programming into policy and incentive frameworks.

    

This project establishes the technical foundation and industry momentum necessary for a widely accepted, automated standard for validating G36 control programming, supporting a more reliable and efficient built environment.