What is the significance of ventilation system performance verification?

• A. It primarily reduces energy use and has little IAQ impact.
• B. It verifies only that the building envelope is airtight.
• C. It is only required for new construction.
• D. It ensures the system meets design intentions for IAQ through measurements and checks.

Answer: (D)

Ventilation system performance verification focuses on confirming that the installed system actually delivers the design intent for indoor air quality. It does this by using measurements and checks to verify that outdoor air delivery, airflow rates, control sequences, and equipment operation match what the design specifies. In practice, this means testing the actual supply air and outdoor air fractions, verifying damper positions and fan speeds, confirming the control logic (including economizers and occupancy-based ventilation), and reviewing documentation from balancing and commissioning activities. This approach ensures IAQ targets are met in operation, not just in theory. It’s not primarily about energy savings, even though energy impacts can occur; it’s about validating that the system delivers the intended IAQ. It’s also not limited to new construction—the verification process applies whenever systems are installed, modified, or re-commissioned in existing buildings. And it isn’t about checking the building envelope’s airtightness, which is a separate concern.