855773520-LEED-v5-ID-C-Reference-Guide-Launch-Edition-1 - Page 226

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PATH 1. VENTILATION ENERGY OR HEAT RECOVERY

Energy Recovery Ventilators (ERV) or Heat Recovery Ventilators (HRV) reduce peak heating and cooling loads associated with ventilation by pre-treating the incoming outside air with heated or cooled air recovered from the exhaust stream.

Ventilation systems supplying a combined total of at least 85% of the project’s outdoor air must have an ERV or HRV with a 70% enthalpy recovery ratio or 75% sensible heat recovery ratio. This includes both base building and project air handling units that supply outdoor air to the project.

Controls for ERVs and HRVs ERVs must have controls to disable energy exchange or bypass air during economizer operation. The requirement does not apply to systems that have design outdoor airflow rates less than 80% and design outdoor air volume less than 10,000 cfm. Refer to ASHRAE 90.1- 2022, Section 6.5.6.1.2.2 Provision for Air Economizer or Bypass Operation for details.

PATH 2. LOW THERMAL CONDUCTANCE

This path rewards reduced heat gains and losses through the building envelope that contribute to lower peak thermal loads. Requirements differ for initial build-outs and alterations of existing buildings.

To apply this path for the project only, the project boundary must have exterior exposure including at least one roof, exterior above-grade wall, or exterior floor that is not slab-on-grade. To assess credit compliance, account for all exterior envelope components within the project boundary.

Projects wholly comprised of interior space may only show compliance at the building level.

Initial build-out Initial build-out projects must document prescriptive compliance with each thermal bridging requirement in ASHRAE 90.1-2022, Section 5.5.5a, ensuring a continuous thermal barrier that minimizes heat conductance associated with thermal bridges. A thermal bridge is an element that penetrates the building insulation, such as a wall and roof intersection, a wall and window intersection, an exterior cladding support, or a beam penetrating the exterior wall assembly.

Account for all thermal bridges in the project’s building envelope, regardless of whether these were constructed for the base building or included in the project scope.

U.S. Green Building Council LEED v5 Reference Guide for Interior Design and Construction, April 2025 Launch Edition 215