If a heating system is a high-efficiency gas furnace, what medium does it usually convey heat through?

A high-efficiency gas furnace typically conveys heat through air. These furnaces utilize a blower to move heated air through ducts and into living spaces, providing comfortable warmth efficiently. Unlike systems that use water or steam, which are typically found in hydronic or steam heating systems, high-efficiency gas furnaces are designed to directly heat air that is then distributed throughout a building.

In high-efficiency models, the combustion process is optimized to extract as much heat as possible from the fuel, often utilizing a two-stage heating process or modulating the flame to adjust to the heating demand. This efficiency translates into warmer indoor spaces while minimizing energy waste, reinforcing the air-based method of heat distribution. Other options, such as water or steam, are characteristic of different heating systems and are not applicable to the functioning of high-efficiency gas furnaces.