How Forced Air Central Split Systems Work

Video Guide for what makes a forced air split central system for heating and air conditioning work. A split central system consists of indoor equipment that includes a gas fired furnace or air handler, and outdoor equipment consisting of a condensing unit or heat pump. They are connected by a pipe called a line set.

The gas fired furnace produces a flame that heats up a wire grid (heat exchanger). The blower blows this air through duct work in the house that comes out outlets to be drawn across the house through a larger duct known as the air return. The air return circulates air across the room, keeping it comfortable, and then returns back to the gas fired furnace where the process repeats.

There are 3 styles of burners: 1 Stage, which just turns on and off; 2 Stage, which has a high and low setting; and the most efficient 3 Stage, in which the modulating increases or decreases based on demand.
The blower motor is available as multi-speed (low, medium and high setting) and variable speed, which is more efficient.

The available configurations for the gas furnace or air handler are Up flow (mounted in basement), Down flow (1st floor application) and Horizontal (for attics or crawl spaces).

These systems are available in cost effective packages or can be purchased as individual components for customization.

During cooling season, the outside unit has refrigerant pipes which transfer refrigerant back to the house and into the evaporator coil. Then, cold air will be transferred while removing humidity in the air. Cold air will be blown by the blower motor through outlets across the room and back to the unit to repeat the process.

Heat pump systems produce heat during the winter. It takes cold outside air and compresses and condenses it to generate heat and that heat is transferred into the furnace to go through the house, repeating the process as before.

Also available is a hybrid (dual fuel) system, which incorporates a heat pump and traditional gas furnace. During moderate times, the heat pump runs on electricity for heating and cooling and is more cost effective. The furnace will kick in automatically when there is greater demand.

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