ID#10371 made on
EAp2 - Minimum energy performance
Rating System Family:
Building design + construction
Clarification is requested regarding whether garage demand control ventilation may be modeled for credit. Garage Ventilation is not addressed by ASHRAE 90.1 – 2007, Appendix G, therefore if savings...
Clarification is requested regarding whether garage demand control ventilation may be modeled for credit. Garage Ventilation is not addressed by ASHRAE 90.1 – 2007, Appendix G, therefore if savings is claimed it must be modeled as an Exceptional Calculation Measure (ECM). Garage demand control ventilation is increasingly becoming standard practice in newly constructed buildings. In order to take credit for this measure as an ECM, it must be demonstrated that the proposed design goes beyond standard practice.
ECMs must be approved by the Rating Authority. As the Rating Authority for LEED projects, the GBCI will accept an ECM for garage demand control ventilation under the following circumstances:
1) Baseline case shall meet the requirements of ASHRAE 90.1-2010, Section 18.104.22.168.5 Enclosed Parking Garage Ventilation. Baseline fan volume shall be based on the minimum required ASHRAE 62.1 parking ventilation rates of 0.75 cfm / square foot. Baseline system fan power shall be calculated at 0.3 watts per CFM.
2) Proposed case shall reflect the actual design. Evidence shall be provided documenting that demand control ventilation strategies are sufficient to automatically detect contaminant levels of concern in parking garages (Carbon Monoxide, Particulates, VOCs, etc. and NO2) and modulate airflow such that contaminant levels are maintained below specified contaminant concentration as identified in ASHRAE 62.1-2010 Addendum d. Evidence shall also be provided that contaminant sensors are placed in space in an appropriate manner for detection of contaminant in question and that the sensors be calibrated yearly.
3) If other activities occur in the garage area, the ventilation for these uses shall be in addition to garage vehicle ventilation.
4) Proposed case shall be modeled such that a minimum air flow of 0.05 cfm/square foot is maintained.
5) A narrative shall describe all Baseline and Proposed case assumptions included for this measure, and the calculation methodology used to determine the projected savings. The narrative and energy savings should be reported separately from the other efficiency measures in the LEED Form.
6) No more than a 75% fan energy savings shall be claimed for this measure.
Related Addenda (Corrections & Interpretations)