If you have central heating and air system this means that you also have a lot of ducts running through the home. These ducts are oftentimes disregarded by many homeowners, but they are an intricate part of the HVAC system.
Without the ducts, your furnace or air handler simply would not be able to properly discharge the air in the home to keep its temperature cooled or heated. However, this system is much more than a highway for air. In order for air to properly heat and cool the home, it has to be circulated throughout the home. And, proper circulation of this air will require the use of multiple vents like the supply vents and the return vents.
Understanding The Trunk Line
The first thing that you need to know about the duct system is that the main route of travel is the trunk line. This will be the biggest part of the system and this is how the air travels from the furnace or air handler to the ducts and vents. The trunk line will start out with a large duct and decrease down every 15 feet or so. This allows the airflow to gain velocity the further it travels.
Understanding The Ducts
Once the air enters the trunk line it has to get to vents in the home. It does this by traveling through the ducts. These ducts are much smaller than the trunk line. In fact, they are usually only 6 to 8 inches in diameter whereas some trunk lines can start out as large as 16 inches. These ducts will be attached to the side of the trunk line and they are responsible for introducing the air into the home through the vents.
Understanding The Vents
The vents in the home are simply the outlets that are either installed in the floor, wall, or ceiling. Some of these vents will force out air while others suck in air. Forced air vents are known as supply vents and the vents that suck in the air are known as return vents.