This method of testing is provided for analyzing and diagnosing building energy simulation software using software-to-software and software-to-quasi-analytical-solution comparisons. The methodology allows different building energy simulation programs, representing different degrees of modeling complexity, to be tested by comparing the predictions from other building energy programs to the simulation results provided by the Rating Software in question.
The specifications for determining input values, the weather data required and an overview for all the test cases containing information on those building parameters that change from case to case is provided in the Standard 140-2007 documentation. The cases are grouped as:
- Building Thermal Envelope and Fabric Load Base Case
- Building Thermal Envelope and Fabric Load Basic Tests
- Low mass
- High mass
- Free float
- Building Thermal Envelope and Fabric Load In-Depth Tests
- Space-Cooling Equipment Performance Analytical Verification Base Case
- Space-Cooling Equipment Performance Parameter Variation Analytical Verification Tests
- Space-Cooling Equipment Performance Comparative Test Base Case
- Space-Cooling Equipment Performance Comparative Tests
- Space-Heating Equipment Performance Analytical Verification Base Case
- Space-Heating Equipment Performance Analytical Verification Tests
- Space-Heating Equipment Performance Comparative Tests
COMNET software is required to perform the ASHRAE Standard 140-2007 suite of software tests and the results of these tests shall conform to the COMNET acceptance requirements. All tests shall be completed in accord with the requirements of ASHRAE Standard 140-2007. The resulting estimates of energy consumption shall fall between the minimum and maximum values established by COMNET, unless a valid explanation is provided. The portfolio folder for Appendix E contains spreadsheets wherein the software vendor enters the results of the Standard 140 simulations for comparison against the criteria. When results from candidate software fall outside the COMNET acceptance range or when candidate software is unable to perform one of the tests, the vendor shall provide an explanation of the reason as per ASHRAE Standard 140-2007 requirements. The portfolio folder for Appendix E also contains a methodology paper that describes how the acceptance criteria were developed.
Using the Spreadsheets
Four spreadsheets are provided in Appendix E for documenting results from candidate software and comparing to the COMNET acceptance ranges. These parallel the spreadsheets provided with ASHRAE Standard 140-2007. For each of the spreadsheets, the fields where data is entered are shaded pale yellow. The tabs where data is entered and where results are reviewed are shown in Table 3-1.
Table 3-1: "Spreadsheets for Verifying Standard 140 Tests"
Spreadsheet |
Enter Data on Tab |
Check Results on Tab |
COMNET Acceptance Range Results 5-2.xls |
A |
A |
COMNET Acceptance Range Results 5-3A.xls |
YD |
A |
COMNET Acceptance Range Results 5-3B.xls |
YD |
Q |
COMNET Acceptance Range Results 5-4.xls |
YD |
Q |