What is the fundamental function of Forced-Air heating systems?

The fundamental function of forced-air heating systems is to heat air in a furnace and distribute it through ducts. This system operates by drawing in cooler air from the living space, heating it by passing it over a heat exchanger, and then pushing the warmed air back into the living spaces through a network of ducts. This method is effective for quickly raising indoor temperatures and is widely used in residential and commercial buildings due to its efficiency and capability to filter air.

The heating process typically involves a thermostat that triggers the furnace when the internal temperature drops below a set point, ensuring consistent heating throughout the environment. This system also allows for the integration of air conditioning, creating a comprehensive HVAC solution that can manage both heating and cooling.

Other options refer to different heating methods, such as hydronic systems that distribute heated water, or electric baseboard heating that uses coils. However, these systems do not involve the forced distribution of heat through ducts, which is characteristic of forced-air heating. Thus, option A accurately identifies the primary operation of forced-air heating systems.