What is the minimum rise/run for vents into a proper chimney?

The correct answer highlights the minimum requirement for the rise for vents that lead into a proper chimney, which is set at a quarter-inch rise per foot of run. This gradual incline is essential for ensuring that any condensation or residue that forms in the vent system can effectively flow back toward the chimney rather than pooling or causing blockages, which could lead to improper ventilation and increased risk of hazardous gases entering the living space.

In a chimney system, having the right pitch facilitates the optimal function of venting by encouraging the upward movement of combustion gases, enhancing draft performance. Adhering to the minimum rise of 1/4 inch per foot helps strike a balance between effective venting and structural feasibility, ensuring that the system operates safely and effectively.

The other choices suggest steeper or shallower inclines, which would not meet the established codes for vent construction and could compromise the system's ability to properly vent gases. A rise that is too steep might be structurally challenging and not allow for proper airflow, while a rise that is insufficient could lead to the aforementioned issues with condensation and blockages. This standard is therefore a critical component in the design and installation of vent systems connected to chimneys.