What is the minimum size of a vent required in a hoistway?

The minimum size of a vent required in a hoistway is determined by ensuring adequate ventilation for safety and performance. The correct answer states that the required vent size is either a percentage of the area of the hoistway or a minimum square footage, whichever is greater. Specifically, this option indicates a vent size of 3.5% of the hoistway area or a minimum of 3 square feet.

This requirement is crucial as it helps to mitigate the buildup of gases, heat, and other potentially hazardous conditions that may arise in an elevator system. By establishing this dual criterion (percentage or minimum square footage), regulations ensure that even in smaller hoistways, there is enough ventilation to maintain safety standards.

Other options may specify only a percentage or only a specific square footage, which could potentially lead to inadequate ventilation in varying hoistway dimensions. Therefore, the dual approach of 3.5% or 3 square feet ensures a standard that meets safety needs across a range of elevator installations.