What must be done to the HVAC system during preparation?

During asbestos abatement preparation, shutting down the HVAC system is crucial to prevent the spread of asbestos fibers throughout the building. When the HVAC system is operational, it circulates air, which can carry harmful asbestos particles to other areas, posing a risk to workers and occupants. Shutting it down effectively contains any potential airborne contaminants within the work area, creating a more controlled environment for safe abatement procedures.

Covering the system, repairing it, or leaving it on would not sufficiently mitigate the risks associated with asbestos exposure. Repairing the system may not be necessary unless there are pre-existing issues, and covering it may not prevent air circulation unless the system is completely shut down. Therefore, shutting down the HVAC system is the most effective method to ensure safety during the abatement process.