Before applying termiticides in crawl space areas, what should be done with plenums?

Before applying termiticides in crawl space areas, it is essential to turn off the plenums. Plenums are spaces or conduits that distribute air in a building's heating and cooling system, often used in conjunction with HVAC systems.

Turning off plenums before termiticide application is critical because it helps to prevent the chemicals from being dispersed throughout the building's air circulation system. By ensuring that the plenums are off, you can minimize the risk of the termiticide being pulled into living spaces or other areas where it could pose a health risk to occupants. This precaution ensures that the termiticides remain effective in the target area without unintended exposure.

In contrast, leaving the plenums on would allow air movement, potentially spreading the chemicals and compromising safety. Insulating them or sealing them might be necessary at other times or for different purposes, but those actions do not directly address the immediate concern of chemical exposure during the application of termiticides.