When placing a fan or blower for positive pressure ventilation ____________.

When using a fan or blower for positive pressure ventilation (PPV), the proper placement is critical for effectiveness. Placing the fan several feet outside of the door is the correct approach because it allows the fan to push a column of fresh air into the building. This creates positive pressure inside the structure, which helps to expel smoke, heat, and other hazardous gases.

Positioning the fan outside rather than inside ensures that the fresh air is directed straight into the building. It also minimizes the risk of back-draft or the fan drawing in hazardous conditions from inside. This method effectively helps in controlling the spread of smoke and aids in fire suppression by improving visibility and conditions for firefighters working inside.

If the fan were placed directly at the door, it might not create a sufficient airflow pattern to optimize smoke removal throughout the area. However, effective ventilation relies on maximizing airflow, which is achieved by positioning the fan correctly outside the entrance.