Question: Are perforated metal wall solar air heating systems eligible for credit under LEED CS EAc2?" Background: The intent of the credit is to "encourage and recognize increasing levels of on-site renewable energy self-supply in order to reduce environmental and economic impacts associated with fossil fuel energy use." "Renewable Energy Systems Eligible for EA Credit 2", "Solar Thermal Systems" (p. 224) states "Active solar thermal energy systems that employ collection panels; heat transfer mechanical components such as pumps or fans, and a defined heat storage system, such as a hot water tank are eligible for this credit." "Systems Not Eligible for EA Credit 2" (p. 224) states excludes "architectural passive solar and daylighting strategies provide savings that are chiefly efficiency related". Perforated metal wall solar air heating systems include a collector panel (the wall) and a heat transfer mechanical component (fan or fans) but typically do not include a defined thermal storage component. Natural Resources Canada considers these to be active systems ("Total energy savings result from four different mechanisms: [including] active solar heating of ventilation air" http://www.canren.gc.ca/renew_ene/index.asp?CaID=50&PgID=347)
The perforated metal wall solar air heating system described is considered an active system and therefore can contribute toward EA Credit 2. The applicant should note that there are no previously approved calculators for the amount of energy offset by such a system and therefore, the applicant must provide detailed calculations, including all assumptions and applicable weather data, during the review process. Applicable Internationally.