Our project is a laboratory building with several different occupancies. We intend to meet the requirements of this credit (LEED 2.1) as follows: System 1) Office Area. This area consists of one conference room and two floors of private offices and open office areas. We will provide three CO2 sensors: one in the conference room and one at breathing level near a return grille in one of the open office areas on each floor to provide a representative reading for all the offices on that floor. The AHU will have a direct outdoor airflow measurement device and the outdoor air will be kept constant during occupied hours. (This conference room would not be considered a densely occupied space per LEED 2.2). System 2) Laboratory Spaces. These rooms will be provided with 100% outside air and 100% exhaust. The CIR ruling of 8/4/2003 stated that a lab space "would require some instrumentation to report on the resulting IAQ conditions to capture the point. CO2 sensors per se may not be required, but a monitoring system for the lab spaces should provide feedback in a form that affords operational adjustments." We propose using the thermostats as a means to monitor the lab IAQ. Thermostats located in the breathing zone would only be satisfied if the supply air (100% OA) was reaching the breathing zone. Operational adjustments to the air distribution system would be made as a result of low occupant comfort should the ventilation effectiveness be low. System 3) Electron Microscope Imaging spaces. These four rooms will be provided with minimal outside air due to the low occupant load relative to the equipment cooling load. We will provide a CO2 sensor in one of the four rooms at breathing level to provide a representative reading for these rooms. The AHU will have a direct outdoor airflow measurement device and the outdoor air will be kept constant during occupied hours. System 4) Clean Rooms. This large room is served by one large AHU, capable of providing 100% OA, and eight smaller recirculating AHUs. The clean room function requires that the outside air and exhaust air be maintained to keep the space positive at 0.02 inches. We will provide a CO2 sensor near the return at one of the circulating AHUs to provide a representative reading for this area. The large AHU will have a direct outdoor airflow measurement device. Do the quantities and locations of the CO2 sensors satisfy this credit for Systems 1, 3 and 4? Will the room thermostats suffice as a monitoring system as discussed for System 2?
The applicant is requesting confirmation on the use of different strategies in order to comply with EQc1 requirements. System 1 - The approach presented is not acceptable. The numbers of sensors proposed do not cover the areas appropriately. For example, if there are more people in one office and other offices are empty, the CO2 sensor will still sense the same CO2 concentrations, in essence under-ventilating the occupied office and over-ventilating the unoccupied ones. System 2 - The proposed method is not acceptable. Satisfying a thermostat is not the same as meeting IAQ requirements. CO2 is used as an indicator of issues with IAQ for the purposes of this credit. Typically, projects with 100% Outside Air (OA) requirements have some form of differential pressure sensors to monitor IAQ. System 3 - One CO2 monitor will be required in each room to meet the requirements of this credit. System 4 - This approach seems reasonable. Locate the CO2 sensor at the return grille of the recirculating air-handler farthest away from the air-handler providing outside air. In your submission, include a drawing of the air-handlers with the OA AHU and the CO2 sensor location clearly marked. The information provided in the CIR indicates that this project could utilize strategies from NCv2.2 to earn this credit. Please refer here for additional information about substituting NCv2.2 credits in NCv2.1 projects: http://www.usgbc.org/ShowFile.aspx?DocumentID=1704 Applicable Internationally.