Lead Performer: Argonne National Laboratory – Argonne, IL
-- GARD Analytics – Arlington Heights, IL
-- JNA – Golden, CO
-- Thermal Energy System Specialists – Madison, WI
-- Big Ladder Software – Denver, CO
DOE Total Funding: $1,600,000
FY18 DOE Funding: $600,000
Cost Share: In kind contributions by vendor members of ASHRAE Standing Standard Project Committees 140 and 205
Project Term: October 1, 2018 – September 30, 2021
Funding Type: Competitive Lab Funding, Merit Review 2018
Related Projects: EnergyPlus, Spawn, Empirical Validation and Uncertainty Characterization, Test Procedures for Building Energy Simulation Tools

Project Objective

ASHRAE Standard 140 “Standard Method of Test for Building Energy Simulation Computer Programs” aims to increase confidence in the use of building energy modeling (BEM) by creating standardized and citable test procedures for validating, diagnosing, and improving the current generation of BEM software. ASHRAE first published Standard 140 in 2001, and updates were published in 2004, 2007, 2011, 2014, and 2017.  The continuing development and maintenance of ASHRAE Standard 140 is a critical part of ensuring that building energy modeling (BEM) engines provide accurate and consistent results to building designers, energy consultants, efficiency program administrators, and product developers.

This project continues BTO’s support for this standard. It aims to increase adoption of the standard, accelerate its development, and reduce the burden on vendors that participate in developing the standard by contributing to published results as well as to those testing against the standard. This will be achieved by adding automation to simulation trials and reporting. The team will develop a user guide for the standard, explore reorganization of the standard to make it more readable, streamline the IRS 179D software submission process, and increase engagement with BEM developers and incentive programs that reference Standard 140.

An important part of this project will be adding empirical tests to Standard 140. The Standard 140 testing framework relies on a mix of three kinds of tests: (1) Analytical tests with closed form solutions, (2) empirical tests with results based on measured data, and (3) comparative tests with neither closed form solutions nor measured data. Comparative tests fill the gaps between analytical and empirical tests for engines that have passed the first two. Collectively, the three kinds of tests form a more robust and complete structure than any could create individually or any two could create without the third. Historically, Standard 140 has relied heavily on comparative and analytical tests because “validation-grade” empirical measurements for whole-building energy simulation have been difficult to obtain. However, well-characterized highly-instrumented test facilities like LBNL’s FLEXLAB (Facility for Low Energy eXperiments) and ORNL’s FRP (Flexible Research Platform) make validation-grade experiments feasible. For the past three years, DOE has funded such validation experiments at these two facilities with the intention of incorporating their results into the standard.

ASHRAE Standard 140 compares results from different engines to establish acceptable ranges for results, isolate anomalies and bugs, and identify areas of need for future BEM research.
ASHRAE Standard 140 compares results from different engines to establish acceptable ranges for results, isolate anomalies and bugs, and identify areas of need for future BEM research.

Project Impact

Building Energy Modeling (BEM) is the basis for a number of building energy-efficiency activities including energy-efficiency standards. These activities could not take place without confidence in building energy modeling engines. ASHRAE Standard 140 is the framework for establishing this confidence in energy modeling engines and—collectively—in the energy modeling enterprise. It also serves as a living engine-neutral test suite that allows an ever-expanding and rising minimum baseline of capabilities among engines available at any given time. The ASHRAE Standard 140 suite is the primary mechanism by which engines are certified for specific purposes. The most notable example for commercial buildings is the list of software qualified for use for application for the 179D tax credit. Many other organizations reference the 179D qualified software list. For residential buildings, RESNET cites Standard 140 to qualify software for the RESNET Home Energy Rating System (HERS).

The primary target audience for ASHRAE Standard 140 are engine developers like DOE (EnergyPlus and Spawn), TESS (TRNSYS), IES (Apache), and Wrightsoft (CSE). Other audiences include codes and standards agencies, energy efficiency program administrators, and building energy modeling practitioners. Standard 140 is cited and used by other ASHRAE Standards such as the 90.1 Standard for minimal energy efficiency in commercial buildings, the International Energy Conservation Code (IECC), the International Green Conservation Code (IGCC), and the energy codes of many nations, states and localities including Canada, China, Japan, and Australia.

This project will accelerate the development and improve the accessibility of Standard 140 while adding new empirical validation test cases.


DOE Technology Manager: Amir Roth
Lead Performer: Ralph Muehleisen, Argonne National Laboratory

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