What is the required minimum distance that doors must be kept horizontally from appliance and equipment vent terminals?

The correct minimum distance that doors must be kept horizontally from appliance and equipment vent terminals is 12 inches. This standard is in place to ensure safety and proper ventilation. Keeping this distance helps to prevent any potential obstruction of the venting system, which is critical for the safe operation of appliances that produce combustion gases.

When vents are positioned too close to obstructions, such as doors, there is a risk of exhaust gases being redirected back into the living space, which can lead to dangerous situations, including carbon monoxide buildup. Additionally, this clearance allows for adequate airflow and prevents physical interference when doors are opened or closed, ensuring that the vent remains unhindered.

Understanding this requirement reflects the broader principles of mechanical systems design, which prioritize safety and efficiency in the installation and operation of ventilation systems.