Master Plumber Practice Exam

The correct answer is 12 feet. A Type B-W gas vent is designed for appliances that use gas and have a venting requirement to ensure the proper operation and safety of the system. According to building codes and safety regulations, the termination point of the vent must be high enough to prevent the accumulation of harmful gases and to promote effective ventilation.

In particular, the requirement for vent termination height is often set at a minimum of 12 feet above the bottom of the wall furnace. This height helps to ensure that exhaust gases dissipate safely into the atmosphere, away from windows, doors, or other openings that may allow gases to re-enter the building. Additionally, it minimizes the risk of down-drafting, which can occur when colder air is drawn back into the vent.

Understanding the importance of proper vent height is critical for system efficiency, safety, and compliance with local plumbing and gas codes, making the 12 feet standard essential for any installation involving a Type B-W gas vent.