Too Many People, Too Little Outdoor Air in a Converted Warehouse

No. CO2 sensors are a control device for demand-controlled ventilation; they do not create outdoor air. In a dense open plan they will simply show elevated CO2 all day if the air handler cannot deliver the design rate.

Do the arithmetic first. Compare the design outdoor-air rate against the standard's requirements using both the per-person and per-area components. At roughly one person per 100 ft², the per-person component alone can approach the entire 0.06 cfm/ft² the unit delivers, and the area component pushes the requirement higher still. The shortfall is structural, not a controls tuning issue.

Evaluate the options honestly:

• Increased ventilation credit: requires delivering more outdoor air than the minimum. Not achievable with the current unit.
• Air-quality testing path: tests whether the space meets concentration limits after construction; it does not fix an undersized ventilation system, and the minimum ventilation prerequisite still applies.
• Flush-out: also does not fix design ventilation; it is a post-construction measure, and it is the one with the three-week schedule cost.

Recommendation: add a tenant-owned dedicated outdoor-air unit or ERV on the roof, sized to meet the required rate, and keep CO2 monitoring as a control strategy rather than a substitute.

This is a design conflict with a straightforward hierarchy of fixes.

1. Separate them physically: relocate the intake louver or extend the duct to a location away from the dock, with clearance from the truck exhaust plume. This is the only fix that works regardless of tenant behavior.
2. Relocate the dock activity: if the intake cannot move, shift idling and staging to the far side of the dock, or reconfigure the approach so trucks do not queue at the louver.
3. Operational controls: anti-idling signage and, more importantly, an enforceable delivery policy. Signage alone is weak; a policy with consequences for carriers is stronger. Include it in the building rules and the lease.
4. Filtration and monitoring: if some exposure is unavoidable, specify higher-efficiency filtration and consider intake air monitoring. Do not use filtration to justify leaving the intake where it is.
5. Entryway system: a proper entryway system at the loading and pedestrian entries reduces tracked-in contaminants and supports the IEQ narrative.

Document the final geometry on the site plan and in the ventilation calculations so the reviewer can see the separation.

Recommended path: fix the ventilation system first, then choose the credit path that fits the new capability.

• Install a dedicated outdoor-air unit or ERV sized to the calculated requirement, ducted to the occupied space and controlled with CO2 monitoring for demand-controlled operation.
• With that capacity in place, the project can credibly pursue the increased-ventilation credit and can still use air-quality testing after construction if the owner prefers it to a flush-out.
• If the owner wants to avoid the three-week flush-out, air testing is the schedule-friendly alternative-but only if the ventilation system is already correct. Testing cannot compensate for an undersized unit.

Documentation to assemble:

• Ventilation rate calculations showing per-person and per-area components against the standard, with design occupancy stated.
• Equipment schedules and cut sheets for the new unit, plus roof structural and landlord approval letters.
• Controls sequence and CO2 setpoints, tied to the commissioning scope.
• Test-and-balance report for both the existing system and the new unit.
• Air-quality test results from an accredited laboratory, if that path is chosen, with the testing protocol and dates.
• Site plan showing intake location relative to the dock, plus the delivery and idling policy.

The test is whether the submittal proves the space gets enough outdoor air at design occupancy, not merely that a sensor was installed.