Air ducts work by acting as a network of channels that distribute heated or cooled air throughout a building, ensuring consistent temperature and air quality in various rooms.
Here's a breakdown of how they function:
- Air Intake: The system begins with an air intake, which draws air from either inside or outside the building.
- Heating/Cooling Unit: The air then passes through the heating or cooling unit (furnace, air conditioner, or heat pump), where it's either warmed or cooled to the desired temperature.
- Duct Trunk: The conditioned air is then pushed into the main duct, often called the duct trunk. This is usually a large, central duct made of materials like sheet metal or fiberglass duct board.
- Duct Pipes (Branches): The duct trunk then branches out into smaller ducts, known as duct pipes or branches, that lead to individual rooms or zones within the building. These smaller ducts are also typically made of sheet metal or flexible ductwork.
- Air Vents/Registers: At the end of each duct branch, there's an air vent or register. These vents allow the conditioned air to enter the room. They often have adjustable louvers to control the direction and volume of airflow.
- Return Air Ducts: Crucially, air duct systems also include return air ducts. These ducts collect air from the rooms and return it to the heating/cooling unit to be reconditioned and recirculated. This creates a continuous loop.
- System Pressure: The entire system relies on a blower fan (usually located within the furnace or air handler) to create pressure and force the air through the ducts.
- Sealing and Insulation: To prevent energy loss and maintain efficiency, air ducts are often sealed to prevent leaks and insulated to minimize heat transfer.
In essence, air ducts provide a pathway for conditioned air to be delivered and recirculated throughout a building, contributing to overall comfort and indoor air quality.
