Our project is a 7 story 163,000 sq. ft. laboratory/vivarium building that is mechanically ventilated with MERV 13 filtration for all air handling units serving the building. Among various other programmed areas, the building has 21 zones of open laboratory spaces that are being MERV 13 filtered, heated, and cooled by the laboratory air handling unit system. To minimize the excessive requirements of outside air into the building for these labs, supplemental recirculated fan coil units are being provided for these 21 zones. The systems (at minimum load conditions) start out by ventilating these labs with 6 ACH (air changes per hour). Upon an increase in load, the VAV (variable air volume) air system will increase the ventilation to these zones to a maximum condition that corresponds to 12 ACH. Upon further need for cooling (based on excessive summer heat through the exterior glazing to these zones), there are 21 individual fan coil units that provide additional cooling to these spaces to satisfy the local temperature sensors. The 12 ACH still comes from the MERV 13 filtered air handling unit systems but the fan coil units are only MERV 8 filtered. The intent for these supplemental systems was to minimize the energy consumption for these transient conditions by not utilizing additional outside air. Since these units fully recirculate their air flows from within these 21 laboratory zones and only activate upon excessive cooling conditions to supplement the flows from the MERV 13 air handling units, does this ventilation scheme meet the intent of EQ credit 5: Indoor Chemical & Pollutant Source Control?