What is the primary function of sealed combustion appliances?

Sealed combustion appliances are designed to pull air needed for combustion from the outside rather than using air from within the home. This function is essential for ensuring that the appliance operates safely and efficiently. By sourcing combustion air externally, these appliances help maintain indoor air quality, as they do not deplete the air supply within the living space. This feature is particularly important in tightly sealed homes where indoor air quality can quickly degrade.

In cases where a sealed combustion appliance is used, there is also a significant reduction in the risk of backdrafting, where harmful gases could be drawn back into the living space from the appliance. Therefore, the primary function of sealed combustion appliances is fundamentally linked to safety and ventilation, making their design critical for effective operation.