What are the two types of gas utilized by residential furnaces?

Residential furnaces primarily utilize two types of gas: natural gas and propane. Natural gas is the most common fuel source for residential heating in areas where it is readily available through pipelines. It is composed primarily of methane, is cost-effective, and produces fewer emissions compared to other fossil fuels.

Propane, on the other hand, is a versatile gas used in areas where natural gas is not accessible, often supplied in tanks. It burns efficiently and is suitable for heating, as well as cooking and hot water heating. Both natural gas and propane are favored in residential settings due to their efficiency and relatively low environmental impact compared to other energy sources.

The other options involve fuels that are less commonly associated with residential furnaces. Butane is typically used in portable stoves and as lighter fluid, while electricity is a separate energy source that does not classify as a gas. Kerosene, often used in specific heater types, is primarily associated with portable heating rather than standard residential furnaces. Thus, the focus remains on natural gas and propane as the principal gas types for home heating.