Florida Home Inspector Practice Test 2026 – Comprehensive Exam Prep

The recommended amount of ventilation for combustion air in a conventional gas furnace is 2 square inches per 1,000 BTUs. This guideline is crucial for ensuring that the furnace operates efficiently and safely. Adequate ventilation allows the furnace to draw in enough air for combustion, which helps prevent incomplete combustion and the buildup of harmful gases, such as carbon monoxide, within the home.

Proper combustion air ventilation is essential not only for the furnace's performance but also for the overall safety of the dwelling. If insufficient combustion air is provided, the furnace may not function correctly, leading to potential risks, including the failure of the appliance or hazardous conditions within the home. Thus, adhering to the 2 square inches per 1,000 BTUs guideline is a standard practice to maintain both efficiency and safety in gas heating systems.