The flue gas outlet of appliances must terminate how far below any door, window, or air inlet?

The requirement for the flue gas outlet of appliances to terminate at least 4 feet below any door, window, or air inlet is a critical safety measure. This regulation is in place to ensure that exhaust gases do not enter living spaces. When flue gases are expelled from appliances, they may contain harmful substances like carbon monoxide, which can pose serious health risks if they backtrack into a building.

By maintaining a distance of 4 feet below any openings, the design minimizes the risk of these gases re-entering through doors, windows, or air inlets, particularly during conditions like wind events that could otherwise push the gases back up toward the openings. It is an important consideration in safeguarding indoor air quality and ensuring the safety and comfort of occupants. Therefore, adhering to this clearance requirement is essential for compliance with safety standards and proper installation practices in oil fuel systems.