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Extracted Content

Use the ASHRAE Standard 90.1, Section 6.6.2 Mechanical System Performance Path analysis to show credit compliance. (Refer to EAp2: Minimum Energy Efficiency guidance on this topic). Extract the building peak coincident heating loads and the building peak coincident cooling loads from the TSPR modeled outputs for the referenced building design and for the proposed building design. Calculate performance using the following equations:

Equation 1. Reference peak (based on modeled outputs from the referenced building design)

𝑅𝐸𝐹𝐸𝑅𝐸𝑁𝐶𝐸𝑝𝑒𝑎𝑘 = 𝐵𝑙𝑑𝑔 𝑝𝑒𝑎𝑘 𝑐𝑜𝑖𝑛𝑐𝑖𝑑𝑒𝑛𝑡 ℎ𝑒𝑎𝑡𝑖𝑛𝑔 𝑙𝑜𝑎𝑑𝑠+ 𝐵𝑙𝑑𝑔 𝑝𝑒𝑎𝑘 𝑐𝑜𝑖𝑛𝑐𝑖𝑑𝑒𝑛𝑡 𝑐𝑜𝑜𝑙𝑖𝑛𝑔 𝑙𝑜𝑎𝑑𝑠

Equation 2. Proposed peak (based on modeled outputs from the proposed building design)

𝑃𝑅𝑂𝑃𝑂𝑆𝐸𝐷𝑝𝑒𝑎𝑘

= 𝐵𝑙𝑑𝑔 𝑝𝑒𝑎𝑘 𝑐𝑜𝑖𝑛𝑐𝑖𝑑𝑒𝑛𝑡 ℎ𝑒𝑎𝑡𝑖𝑛𝑔 𝑙𝑜𝑎𝑑𝑠+ B𝑙𝑑𝑔 𝑝𝑒𝑎𝑘 𝑐𝑜𝑖𝑛𝑐𝑖𝑑𝑒𝑛𝑡 𝑐𝑜𝑜𝑙𝑖𝑛𝑔 𝑙𝑜𝑎𝑑𝑠

Equation 3. Performance target

𝑃𝑒𝑟𝑓𝑜𝑟𝑚𝑎𝑛𝑐𝑒 t𝑎𝑟𝑔𝑒𝑡= 𝑅𝐸𝐹𝐸𝑅𝐸𝑁𝐶𝐸𝑝𝑒𝑎𝑘 × 𝑀𝑃𝐹

where:

MPF = Mechanical performance factor for project’s location and climate zone per ASHRAE Standard 90.1-2022, Table L5-4

Equation 4. % improvement

𝑃𝑅𝑂𝑃𝑂𝑆𝐸𝐷𝑝𝑒𝑎𝑘 % 𝑖𝑚𝑝𝑟𝑜𝑣𝑒𝑚𝑒𝑛𝑡= 100% − 𝑃𝑒𝑟𝑓𝑜𝑟𝑚𝑎𝑛𝑐𝑒 t𝑎𝑟𝑔𝑒𝑡

PATH 3. ENERGY SIMULATION

Projects that comply with EAp2: Minimum Energy Efficiency using the ASHRAE 90.1 Appendix G Performance Rating Method (PRM) can use the PRM modeled results to show compliance with this path.

This path is the most appropriate selection for projects with high process loads or projects with significant quantities of laboratory or kitchen exhaust. Unlike Path 1 and Path 2, this path allows credit for lower plug and process loads documented using ASHRAE 90.1 Section G2.5 Exceptional Calculation Methods (See EAc3: Enhanced Energy Efficiency guidance for further information).

U.S. Green Building Council LEED v5 Reference Guide for Building Design and Construction, April 2025 Launch Edition 297