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  • Pacific Northwest National Laboratory – Richland, WA
  • GARD Analytics – Arlington Heights, IL
  • Karpman Consulting – Glastonbury, CT

Performance Period: Oct. 1, 2019 – Sep. 30, 2022

Funding Type: FY19 Lab Call

Budget: $2,100,000

Related Projects: ASHRAE Standard 140

Project Objective

BEM software is commonly used document building performance relative to a reference energy efficiency code for applications ranging from code compliance, to green certification, to utility incentives. The general procedure involves comparing a simulation of the proposed building to a simulation of the building modified to meet the minimum prescriptive requirements of the corresponding standard. The modified building is often called the "baseline" building, while the procedure may also dictate some modifications to the proposed building as well. ASHRAE Standard 90.1 "Energy Standard for Buildings Except Low-Rise Residential Buildings" includes two such procedures: Energy Cost Budget (ECB) also known as "Chapter 11" and Performance Rating Method (PRM) also known as "Appendix G".

The modifications to the proposed building and the generation of the baseline building are detailed, mechanistic procedures often referred to as "rulesets". They are tedious to implement manually and are prone to interpretation differences, human error, and, sometimes, gaming. Significant effort is spent implementing these procedures which underpin important transactions but do not directly inform or improve building performance.

To alleviate this burden many software vendors have automated these rulesets. Although whereas there exists a testing standard that promotes accuracy and consistency among BEM engine implementations (ASHRAE Standard 140 "Method of Test for Building Energy Simulation Programs"), a corresponding ruleset testing standard does not exist.

This project will provide leadership and technical assistance for a new proposed standard that attempts to address this gap, ASHRAE Standard 229P "Evaluating Ruleset Implementations in BEM Software". The standard will develop a reporting schema and an open-source checking tool that will inform modelers whether baselines, created either automatically or manually, comply with ruleset standards. While the general framework is intended to be generic, the committee will target ASHRAE Standard 90.1-2019 Appendix G as its first ruleset and targets the 2022 code cycle for initial publication.