What is a Duct in an HVAC system?

A duct is a specialized housing for the airflow in an HVAC system. It is usually made of sheet metal or fiberglass and is used to direct and distribute the airflow from the furnace, air conditioner, or heat pump to the various rooms in the building. The ductwork also helps to return the air back to the unit for reheating or cooling.

Ducts come in different sizes and shapes depending on the type of HVAC system they are used with and the layout of the building. For example, round ducts are typically used with forced-air systems while rectangular ducts are more common with gravity systems. The size of the ducts also varies depending on the amount of airflow that needs to be delivered to the rooms.

Ducts are usually hidden from view behind walls, in attics, or underneath floors. However, they can also be exposed in some cases such as when they run through crawl spaces or unfinished basements. If the ductwork is not properly sealed and insulated, it can leak air and cause the HVAC system to work less efficiently.

What is the difference between a vent and a duct?

A duct is a pathway that is used to transport air from one location to another, whereas a vent is an opening that allows air to enter or exit a space. Vents are typically located on the exterior of a building, whereas ducts are usually hidden from view.

Types of ducts in HVAC

There are 2 main types of ducts used in HVAC systems: supply ducts and return ducts.

How does duct work?

  1. Supply ducts deliver air from the furnace, air conditioner, or heat pump to the rooms in the building. The size of the supply ducts is based on the amount of airflow that needs to be delivered to the room.
  2. Return ducts help to return the air back to the furnace, air conditioner, or heat pump for reheating or cooling. The size of the return ducts is based on the amount of airflow that needs to be returned to the unit.

HVAC duct material

Ductwork can be made of different materials such as:

  • metal,
  • fiberglass,
  • or plastic.

Metal ductwork is more common in commercial buildings, while fiberglass or plastic ductwork is more common in residential buildings.

HVAC duct design

Ductwork is usually designed by HVAC engineers or contractors. The design of the ductwork depends on the type of HVAC system, the layout of the building, and the amount of airflow that needs to be delivered to the rooms.

Conclusion

Ducts are an important part of any HVAC system and need to be properly designed and installed for optimal performance. Improperly sized or installed ducts can lead to a number of problems such as reduced airflow, poor indoor air quality, and higher energy bills.

Therefore, it is important to consult with a professional HVAC contractor to ensure that your ductwork is properly sized and installed.

Related Links

Supply and Return Vents: What’s the Difference and What Exactly Do They Do?

How Does a Duct System Work

The Basic Principles of Duct Design

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