A connector connected to a chimney flue must be at least how many inches above the lowest portion of the interior of the flue?

The requirement for a connector connected to a chimney flue to be at least 12 inches above the lowest portion of the interior of the flue is tied to safety and performance considerations in HVAC installations. This height helps ensure proper venting and helps prevent issues such as backdrafting, which can occur if the connector is too low, potentially causing harmful gases to enter living spaces.

Additionally, maintaining this minimum height helps facilitate the correct flow of combustion gases, reducing the likelihood of condensation forming within the connector and flue. This condensation can lead to corrosion and degrade the efficiency of the system over time. A 12-inch elevation is a standard that supports effective operation while adhering to safety regulations, ensuring that the system can operate safely and effectively over its lifespan.