Duct Transitions
Air ducts must connect according to the specific shape of your home. The pipes and trunks use duct transitions to connect. There are many types of duct transitions and specialized connectors.
They join to make pathways for air to move through your home.
The faster you drive, the harder it is to make a sharp turn. The same goes for airflow in a duct. If there are transitions at tight angles, airflow gets restricted. That is why their placement is so critical.
Some connectors include turning vanes, cleats, and takeoffs. Branch duct takeoffs are standard and come in myriad shapes and styles.
- Round Takeoffs: most cost-effective and commonly used
- Directional Takeoffs: metal scoop or turning vanes protrude out in order to “grab” air from the duct and direct it into a new path
- High-Efficiency Takeoffs (HETO): rectangular to round design that is higher priced
- Rectangular Takeoffs: offer a smooth path for air to move
Plenum
A plenum is a large container that stores air for your HVAC system and is attached to the various ducts. Imagine the plenum as a super highway and the branch duct takeoffs as exit ramps to side roads (ducts going to each room).
Usually, there are two plenums to your ductwork. Your HVAC system will fill the supply plenum with cooled or heated air sent through the ductwork. As the cooled or heated air enters a room, it pushes the existing air into another group of ducts.
These ducts transfer any returned air to the return plenum. Then, the returned air is directed outside through a flue or filter and sent back through the system.
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