What is the other category paired with gravity warm-air furnaces in heating systems?

Gravity warm-air furnaces operate by relying on the natural tendency of warm air to rise without the aid of fans or blowers. This type of system allows warm air to circulate throughout a space primarily due to convection.

In the context of heating systems, forced warm-air furnaces are the counterpart to gravity systems because they use mechanical means, such as blowers or fans, to distribute heated air more efficiently and rapidly. This forced circulation can improve comfort levels and address heating needs in larger or more complex spaces, where natural circulation might not be sufficient.

The distinction between gravity and forced warm-air systems is important in understanding various heating methods and their applications in home inspection, as it affects not only functionality and efficiency but also how systems should be maintained and assessed during inspections.