Notice how there is little to no smoke movement while the blower door fan is off. This indicates minimal air movement through the duct system under normal conditions.

The next video demonstrates how airflow changes once the blower door is activated — revealing duct leakage points using a smoke pen.

This process is part of a comprehensive energy audit and helps identify leaks that can increase cooling costs and reduce HVAC efficiency.

This video demonstrates how a smoke pen is used during a blower door test to detect air leakage in ductwork. Notice the increased smoke movement — this confirms the presence of gaps or openings that allow unconditioned air to enter the duct system or conditioned living space.

Leaky ducts reduce HVAC efficiency, drive up cooling costs, and force the system to work harder to maintain indoor comfort. Identifying and sealing these leaks can significantly lower your monthly energy bill and improve overall home performance.