ID#247 made on
EQc1 - Carbon dioxide (CO2) monitoring
LEED BD+C: New Construction
We are in the process of designing a high school in Virginia. The school has the following main areas: Gymnasiums, Auditorium, Kitchen, Commons and Dining, Administration, and Classrooms. All areas, e...
We are in the process of designing a high school in Virginia. The school has the following main areas: Gymnasiums, Auditorium, Kitchen, Commons and Dining, Administration, and Classrooms. All areas, except the classrooms, are served by Rooftop Air Handling Units. These rooftop units each have CO2 sensors in the return air ductwork that varies the amount of outside air brought into the building to maintain the indoor CO2 levels per LEED requirements. The classroom areas, however, are conditioned by fan coil units. Ventilation air for each space is provided by 100% outside air Heat Recovery Units. These units are constant volume and deliver a constant volume of outside air to each space based on the estimated peak occupancy of that space. The outside air flow rate does not vary with occupancy, but instead provides 100% of the design outside air to the space whether there is one person in the room or the room is full. In this way, although we are not providing "operational adjustments" noted in the LEED credit requirements, we are always bringing in the full amount of outside air and thus the CO2 parts per million requirements should be met. With this design there is no adjustment to the outside air rate to be made because we can't bring in more than 100% design outside air. This approach seems to meet the intent of the credit as the CO2 levels will be satisfied, but not the "operational adjustments" criteria. QUESTION Would this approach be approved for a LEED credit?
REVISED 08/31/01: (The original credit inquiry ruling was sent on 08/07/01. Your request for clarification of that ruling is answered below.) The primary intent of the credit is to provide indoor air quality monitoring to sustain long term occupant health. The monitoring should provide feedback in a form that affords operational adjustments. As described, the 100% outside air system is intended to provide the maximum outside air volume, but does not provide any instrumentation to report on the resulting IAQ conditions, and thus cannot be used to capture the point. By providing a monitoring system that can give feedback on the space ventilation performance, operational adjustments to outside air volumes, air changes, mixing boxes, distribution etc. (either automatic or manual) can be made to correct problems. Applicable Internationally.
Related Addenda (Corrections & Interpretations)