Which factor is least likely to be controlled during mold remediation?

The least controllable factor during mold remediation is the time of day. This is because, while conducting remediation, the schedule may be influenced by external factors such as the availability of personnel, regulatory compliance, and the comfort of occupants in ongoing projects, which can limit the control over when work can be performed.

In contrast, relative humidity is actively managed through dehumidifiers and HVAC adjustments to create an environment that discourages mold growth. Airflow direction can be controlled by positioning fans and defining containment areas to prevent cross-contamination. The presence of HVAC systems is also a factor that can be managed during remediation by ensuring they are either used appropriately or temporarily shut down to limit the spread of spores. Thus, while restoration efforts involve adjustments and careful management of environmental factors, time is a variable that cannot be controlled as precisely as the others.