ID#5792 made on
EQp1 - Minimum IAQ Performance
LEED BD+C: New Construction
Project information: Chicago, IL Urban Site, Large Retail Store The project team requests review of the proposed IEQp1 compliance path detailed below: The projects engineering team has found thr...
Project information: Chicago, IL Urban Site, Large Retail Store The project team requests review of the proposed IEQp1 compliance path detailed below: The projects engineering team has found through testing and ongoing performance monitoring, that the air quality in the store can be properly maintained with less than the outdoor air amount required from the ventilation rate procedure method for retail sales. A study field testing the ventilation design, pollutant levels and IAQ of a Prototype Store located in a cold climate, has been completed and documented by an independent research center. The study has been submitted to USGBC for review as part of this CIR. The study evaluates different retail product mixes and tests the stores IAQ through seasonal extremes including warm humid, summers and cold winters. Multiple measurements were performed corresponding to different ventilation values of outdoor air. The outside air quantity shall be varied between a minimum of 0.15 CFM per square foot and 0.30 CFM per square foot based on CO2 measurements in the occupied zones. The minimum of 0.15 CFM per square foot has been determined to provide good indoor air quality in a study performed for the project owner by the Minnesota Building Research Center. When properly utilized, this compliance methodology offers designers the opportunity to optimize energy use, HVAC equipment selection, system design and IAQ. Please advise on whether or not this compliance methodology is acceptable for IEQp1. Thank you for your consideration.
Yes, the project does comply with IEQp1 via this proposed methodology provided the building design complies with the following: 1. CO2 shall be measured within the "breathing zone" of the occupied space as defined in Standard 62.1-2004. (Return air sensors cannot be used since their readings can be affected by short-circuiting supply air and duct leakage.) 2. CO2 sensors shall be certified by the manufacturer to have an accuracy of no less than 75 ppm, factory calibrated or calibrated at start-up, and certified by the manufacturer to require calibration no more frequently than once every 5 years. 3. The outside air quantity shall be varied from 0.15 CFM per square foot at space CO2 concentrations equal to ambient concentration, proportionally up to 0.30 CFM per square foot when space CO2 concentration is equal to or higher than the ambient concentration plus 600 ppm. Ambient concentration may be measured with another CO2 sensor or it may be assumed to be constant at 400 ppm.
Related Addenda (Corrections & Interpretations)