Which factor might lead to inefficiencies in a gas furnace's operation?

Poor insulation in the home is a crucial factor that can lead to inefficiencies in a gas furnace's operation. When a home is inadequately insulated, it allows outside air to enter and conditioned air to escape more easily. As a result, the furnace has to work harder to maintain the desired indoor temperature, leading to increased energy consumption and higher utility bills. The heat produced by the furnace can quickly dissipate through poorly insulated walls, roofs, or floors, which means continuous cycling of the furnace to compensate for the lost heat.

In contrast, a high AFUE rating indicates that a furnace operates efficiently, converting a significant amount of fuel into usable heat. Regular maintenance ensures that all components of the furnace are functioning properly and helps prevent breakdowns, which can significantly affect efficiency. Enhanced airflow typically promotes better efficiency by ensuring that heated air circulates effectively throughout the home.

In summary, the poor insulation scenario directly impacts how efficiently a gas furnace can operate, requiring it to exert more effort to achieve heating, thus leading to inefficiencies.