Which condition might indicate poor ventilation in the furnace area?

Backdraft is a condition that typically indicates poor ventilation in the furnace area. It occurs when combustion gases, instead of being expelled outside, are pulled back into the interior of the building. This can happen when there is insufficient airflow to allow the furnace to exhaust properly. Poor ventilation can create a negative pressure situation, causing exhaust gases to reverse their flow, which can lead to dangerous situations, including carbon monoxide buildup.

The presence of backdraft signifies that the air balance within the space is not adequate, potentially due to blockages, improper ducting, or an imbalance between air supply and air pressure in the environment. Ensuring proper ventilation is essential for safe and efficient furnace operation, and awareness of backdraft can help pinpoint issues that need to be addressed in the heating system and the overall ventilation setup.