According to the Two Permanent Openings Method, what is the maximum distance one opening must commence from the top of the enclosure?

In the context of the Two Permanent Openings Method for venting, the regulation specifies that when designing ventilation openings for an enclosure containing propane or similar gases, it is crucial for safety and proper ventilation management that one of the openings be situated no further than a certain distance from the top of the enclosure.

The highest point of gas accumulation in an enclosure is typically near the ceiling, since gases like propane are heavier than air. To ensure effective venting and minimize the risk of gas accumulation, one permanent opening must commence no more than 12 inches from the top. This distance allows for sufficient airflow and helps to expend any potential build-up of gas, thereby reducing the risk of hazardous conditions.

This methodology reflects a fundamental principle in propane safety regarding adequate ventilation to ensure that any leaks are quickly dissipated and do not pose a danger.