What advantage does forced draft provide in a furnace?

Forced draft systems in a furnace provide significant advantages by utilizing fans or blowers to push air into the combustion area, which helps maintain a specific airflow and pressure within the furnace. This regulation of pressure is crucial for optimal combustion efficiency and ensures that the furnace operates correctly under varying conditions.

When the pressure inside the furnace is consistent, it helps to prevent backdrafts or the escape of combustion gases into areas where they could be hazardous. A well-regulated pressure also supports improved combustion process efficiency, leading to better fuel utilization and reduced emissions.

The other options do not align with the primary function of forced draft. While it does indeed influence air mixing and can increase air velocity, the primary and most impactful advantage is in managing and regulating the pressure, which is essential for efficient and safe furnace operation.