How can you verify that air is exiting outdoors and not building up in the attic or crawlspace?

How can you verify that air is exiting outdoors and not building up in the attic or crawlspace?

• A. Watch for a change in room humidity and feel air at the attic vent.
• B. Only rely on the interior cabinet temperature.
• C. Listen for a loud buzzing sound in the wall.
• D. Observe the exterior vent for strong airflow while the dryer runs and feel for airflow at the vent opening; a smoke pencil test can help.

Answer: (D)

To verify that dryer exhaust is leaving outdoors and not accumulating in the attic or crawlspace, you want a direct check of the airflow path. Look at the exterior vent while the dryer is running and feel the airflow at the vent opening. If you sense a steady, strong flow and the vent cap moves, that indicates the exhaust is actually escaping outside. A smoke pencil test adds a clear visualization: release a small plume near the dryer connection and watch the smoke. If the smoke is drawn toward the vent and exits outside, you’re seeing the correct path; if the smoke lingers, pools, or drifts back into the attic or walls, there are leaks or a backdraft that could cause buildup indoors. Interior indicators like room humidity or cabinet temperature aren’t reliable proof of where the air is going, and a loud buzzing in the wall doesn’t confirm the exhaust route. Using exterior airflow and a smoke pencil test gives a practical, observable check of the system’s actual exhaust direction.

To verify that dryer exhaust is leaving outdoors and not accumulating in the attic or crawlspace, you want a direct check of the airflow path. Look at the exterior vent while the dryer is running and feel the airflow at the vent opening. If you sense a steady, strong flow and the vent cap moves, that indicates the exhaust is actually escaping outside. A smoke pencil test adds a clear visualization: release a small plume near the dryer connection and watch the smoke. If the smoke is drawn toward the vent and exits outside, you’re seeing the correct path; if the smoke lingers, pools, or drifts back into the attic or walls, there are leaks or a backdraft that could cause buildup indoors. Interior indicators like room humidity or cabinet temperature aren’t reliable proof of where the air is going, and a loud buzzing in the wall doesn’t confirm the exhaust route. Using exterior airflow and a smoke pencil test gives a practical, observable check of the system’s actual exhaust direction.