What is the essential property of a central furnace?

A central furnace is designed to heat a building by distributing warm air through ductwork or other means. The essential property of a central furnace being self-contained means that it has all the necessary components and systems operated within one unit, which includes the heat source, blower, and any controls needed to operate efficiently. This self-contained structure allows for centralized control of heating, making it efficient and effective for maintaining consistent temperatures throughout the space it serves.

Features like portability, being electric, or operating on renewable energy are not fundamental to the concept of a central furnace itself. While some central furnaces can be electric, not all are, and they can also run on gas or other fuels. Additionally, while certain systems may incorporate renewable energy, it’s not a defining characteristic of all central furnaces. Thus, the defining aspect is that a central furnace is indeed self-contained, providing a comprehensive solution for building heating needs.