During which phase is a CxT's involvement primarily focused on verifying indoor air quality?

The correct answer centers around the Post-acceptance phase, where the focus sharpens on verifying indoor air quality. During this phase, the building systems have been installed and are operational, allowing the commissioning technician (CxT) to assess factors like ventilation, humidity, and pollutant levels. It is during this time that the CxT measures and evaluates indoor air quality against the standards and specifications set forth during the design.

In this phase, it is critical to ensure that the systems not only function as intended but also contribute positively to the health and comfort of occupants. Assessing systems after acceptance also allows for any adjustments or calibrations to be made following real-world performance data.

In contrast, the other phases tend to focus on different aspects. The Pre-construction phase involves planning and coordination, the Design phase centers on evaluating systems before they are built, and the Acceptance phase is generally about verifying that systems meet requirements upon project completion. While indoor air quality may be discussed in these phases, the Post-acceptance phase is where the actual verification occurs in a live environment, making it essential for confirming that the building meets air quality standards for its occupants.