Know More About How do Air Ducts Work

Air Ducts Work

Commercial businesses use the HVAC system to maintain the right temperature so that employees can work comfortably. HVAC ducts circulate cooled or heated air throughout the building. Ductwork directs conditioned air to the areas it is most needed. What components make up an HVAC system? How do air ducts function?

The Ductwork System’s Main Components and How They Work

Duct systems are an essential part of any commercial building’s climate control. They distribute the conditioned air evenly throughout a building, increasing comfort and saving energy. Here are the major parts of ductwork with a brief description of their operation.

Ducts (Pipes & Trunks)

Duct pipes or trunks are usually made from sheet metal and are an integral part of a commercial HVAC system. These tubes attach to an air handler to transport the heated or cooled air to the supply registers. Another set of duct pipes collects the used air from the return grilles and returns it to the HVAC unit for expulsion or filtering. To circulate the air around buildings, duct pipes can branch from the duct trunk.

It is important to ensure that trunks and duct pipes are properly sized to provide efficient airflow. They should not be too small. The system won’t be able to move enough air. If they are too big, the system could be inefficient, which could result in energy losses.

Duct Transitions

Duct transitions connect two or more ducts with different materials and parts. This ensures that airflow is not interrupted. They are usually made from metal and can come in a variety of sizes and shapes.


The plenum, a large chamber within the ductwork, is located in the ductwork. In an HVAC system, there are typically two plenums. The supply plenum stores heated or cooled air until it can be distributed evenly throughout the building. The old air is removed from the rooms and pushed into other ducts before being transferred to the return. The air is then either recirculated back into the system or taken outside via a flue.

Registers of Supply

The supply registers are openings in walls or ceilings that allow cooled or heated air into a room.

Return Grilles

Return grilles allow heated or cooled air to pass through openings in walls or floors to return to the return plenum.


A damper regulates airflow through a conduit. You can open or close it to regulate the airflow through the duct.

Insulation with ducts

Insulating ducts can make a huge difference in the efficiency of commercial HVAC systems. Insulating ducts will keep the conditioned air within the ducts, which reduces energy loss and saves money.


Flues are tubes that carry toxic gases from the HVAC unit to the outside. Flues are used to expel any air that is not able to be recirculated through the return plenum of your HVAC system. Flues are usually made from metal and can be either rectangular or round.

Refrigerant Lines

Refrigerant lines are usually made from copper and are essential in commercial HVAC systems. The refrigerant line is a tube that carries the refrigerant to a compressor. This allows the HVAC unit to heat or cool the air.

Air Handler

The air handler typically contains the fan, coils, and filters that regulate the airflow in the building. A duct connects the air handler to the HVAC unit. The fan circulates air through the duct pipes into the building.

Drain Pans and Lines

The water is removed from the air by drain pans and lines. Condensation builds up in ductwork during heating and cooling. This moisture is collected in a drain pan and expelled to the exterior of the building through drain lines. This function is essential in an HVAC system that works efficiently because damp conditions can lead to corrosion and rusting.

Materials for Air Ducts

Commercial air conduits can be made from a variety of materials, including galvanized steel and aluminum. However, fiberglass is the most popular. Each type of ducting comes with its advantages and disadvantages.


Aluminum is the most common material used for air ducts. Aluminum is lightweight and durable, making it easy for you to work with. It is also resistant to corrosion, making it an excellent choice in humid environments. Aluminum is not as heat resistant as other materials so it shouldn’t be used for applications that will expose the ducts to high temperatures.

Galvanized Steel

Galvanized steel is strong and resistant to corrosion, making it an excellent choice for businesses that are subject to a lot of moisture. Galvanized steel can withstand heat, which makes it an excellent choice for environments that may see ducts exposed to high temperatures. Galvanized steel can be harder to work with than other materials because it is heavier than other materials.

Fiberglass Ducts

Fiberglass ducts use lightweight materials that don’t conduct heat. They keep the air inside the ducts cool. Fiberglass ducts are a great option for businesses looking to cut down on energy costs. They don’t lose as much air as other materials, making them an ideal choice. Fiberglass ducts can also be cleaned easily and are resistant to corrosion. They are less durable than other materials and may not be used in areas that are prone to damage, or are subject to high-stress levels.

Flexible Ducting

Flexible ducting allows air ducts to be bent or twisted from materials. It is a great choice for companies who need to install air conduits in tight areas. It comes in a variety of sizes and can easily be cut to any length.

How the Air Duct System Works

Air Duct Systems distribute conditioned air throughout buildings. For this process to work properly, the air must first be heated or cooled by an HVAC unit.

The coils are located within the air handler. The refrigerant lines transport the refrigerant from HVAC units to the coils where it is either cooled or heated.

The drain pan collects the condensate created by this process. The condensate can be expelled to the outside by drain pipes. Flues release noxious fumes from heating and cooling to the exterior of the building.

The heated or cooled air is kept in the supply plenum, where it is circulated in the air handler by fans.

These pipes carry the cooled or heated air through the air duct pipes and deliver it to the desired rooms.

As the fresh air enters a space, the draft pushes out the old air from the floor or walls into another set of duct pipes. These pipes connect to the return plenum. The return plenum is where the air is filtered, recirculated into the HVAC system, or removed via a flue.

To maintain efficient and adequate airflow, each component must work properly.

Professionally cleaning your duct system will make sure that your building remains safe and healthy, and that the air quality is high.

When should you have your ductwork repaired or replaced?

If your ductwork is leaking or damaged, it should be replaced or repaired. A damaged duct system component can reduce the efficiency of your HVAC unit, which can cause indoor air pollution.

Leaking ducts can also lead to moisture problems. If moisture builds up, it can cause damage to your ceilings, walls, floors, and ceilings. This can lead to mold growth and mildew which pose a serious health risk.

It is normal to have to replace some air duct components in your HVAC system over time. The part that is most in need of updating will determine how much your HVAC system needs to be renewed. New furnace models don’t come with the same parts as older models. Even if the condition is acceptable, this could mean that you need to replace other parts.

The ductwork that is properly maintained and cared for can last between 10 and 15 years. If you have any concerns about your ductwork, or if they are in dire need of repair or replacement, it is worth having them checked by professionals.

Contact us

If you are looking for air duct cleaning in DFW tx, then we at Organic Home Service offer different types of services such as air cleaning, restoration, insulation services, and many more at the most affordable prices. Now we have many technicians who work all over the metroplex to take care of your home’s needs. For more details, visit our website or call us.

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