The correct orientation of a combustion air intake elbow in a two-pipe vent system is crucial for what reason?

The correct orientation of a combustion air intake elbow in a two-pipe vent system is crucial for ensuring proper airflow. This is because the combustion process depends heavily on the adequate supply of air for efficient burning of fuel. If the elbow is not positioned correctly, it can restrict the flow of combustion air, leading to incomplete combustion. This inadequate air supply can result in decreased efficiency of the furnace as it struggles to maintain a proper fuel-to-air ratio, which is essential for optimal performance. Additionally, improper airflow can lead to a buildup of harmful gases within the system, potentially creating safety hazards. Therefore, maintaining proper orientation directly affects the operational efficiency and safety of the gas furnace system.