This document is a detailed reference and modeling guide for using the performance rating method in Appendix G of Standard 90.1-2016. These modeling procedures may be used both to show compliance with the standard and to qualify for beyond-code programs. The 2016 modeling procedures can also be used to show compliance with previous versions of Standard 90.1. This manual is intended to be used for buildings that are in the planning, design or construction phases and within the scope of ASHRAE Standard 90.1.
It is not the intent of this manual to change the baseline building defined by the PRM or the underlying standards. The COMNET manual is intended to work in series with, not in parallel with the PRM. The procedures and processes described in this manual are intended to provide consistency and accuracy by filling in gaps and providing additional details needed by energy modelers and software developers. COMNET has made every attempt to maintain consistency; however this document has been created independently from ASHRAE and Standing Standard Project Committee (SSPC) 90.1 and is neither sanctioned nor approved by either of those entities.
When the performance rating method does not establish a baseline, the PRM sometimes gives the rating authority the ability to establish a baseline. In some instances, the COMNET modeling guidelines establish a baseline where one does not exist in Standard 90.1, thereby assuming the responsibility of the rating authority. Examples include plug loads and commercial refrigeration. In other instances, the baseline building specification in the PRM was not specific enough and these guidelines expand on the definition to eliminate ambiguity. The purpose of these elaborations and expansions is to reduce ambiguity and offer credits for energy efficiency measures not addressed by Standard 90.1.