What is the minimum height requirement above the level of a walkway for the vertical termination of mechanical draft systems?

The minimum height requirement for the vertical termination of mechanical draft systems above the level of a walkway is established to ensure safety and proper ventilation. This requirement is set to prevent any potential hazards to pedestrians and to ensure that exhaust gases do not create a risk of inhalation or cause other safety issues.

Choosing a height of 7 feet provides sufficient clearance above walkways, allowing individuals to pass without the danger of contact with the exhaust or draft termination. This height is also in alignment with safety standards that seek to minimize risks associated with working or walking in proximity to exhaust systems. The 7-foot requirement helps to ensure that the system operates effectively while promoting safety.

The other heights suggested do not meet the safety standards and may be inadequate for providing the necessary clearance, thus posing a risk for anyone using the walkway.