During HVAC inspection, which of the following questions needs to be addressed?

The inquiry regarding whether the HVAC system was operating at the time of the fire is crucial because it directly impacts the assessment of potential fire spread, smoke damage, and the overall condition of the indoor environment after the incident. If the HVAC system was running during the fire, it may have circulated smoke and contaminants throughout the building, complicating the cleaning and restoration process. This information helps technicians understand the extent of contamination in different areas and informs their approach to remediation.

In contrast, while the operation of the air conditioning, the age of the system, and how long the HVAC was off may provide some context or additional information, they do not have the same immediate bearing on the condition of the environment post-fire or the necessary actions for proper remediation. Addressing whether the system was operational during the fire allows for a more targeted assessment and planning for cleaning, which is why it stands out as the most critical question in the context of HVAC inspection following a fire incident.