Is Round Ductwork Better than Rectangular Ductwork?

You may have been at a restaurant or a store and looked up at the ceiling and saw big pipes between the rafters. These pipes are ducts and they help move air from the building’s HVAC system into the store. Looking at these ducts, you may have noticed that they are in different shapes. Some ducts are round like big drinking straws, while others are rectangular and boxy. 

Why are there different shapes of ductwork and is round ductwork better than rectangular air ducts? The answer often depends on the needs of the HVAC system, and the location of the ducts in the building.

The team at Hans Heating and Air explains the difference between the common ductwork shapes you might see and help you understand why some shapes are better than others.

Why Are There Different Air Duct Shapes?

Ductwork distributes both hot and cold air throughout the year. Cold air makes ductwork contract, and hot air makes ductwork expand. This frequent expanding and contracting can cause ductwork to develop leaks and cracks over time. It’s not just the air inside the ducts that can make it expand and contract, the temperature around the ducts as well can have an effect. 

This is why ductwork is often insulated, to protect the ducts from developing leaks. However, ductwork that is smooth and non-porous is good for mold and mildew growth prevention. Adding insulation can create a better environment for these contaminants to grow, which can lower indoor air quality. 

When looking up at the ceiling of a variety of buildings, you may realize that no two buildings have the same configuration of ductwork. You might also notice different shapes connecting to each other. Each building has different HVAC needs. Ductwork comes in a variety of shapes, sizes, and materials and each has its own advantages and disadvantages. For now, we’re just going to focus on round and rectangular ductwork shapes.

Round Ductwork

Round ductwork is the most common type of ductwork. It is fairly flexible, bendable, and usually insulated so that it can deliver air quietly. This ductwork looks like a drinking straw in that it has a coil inside it that keeps parts of it rigid, while other sections can bend around corners. Round ductwork is usually quicker and cheaper to install. 

Because of the round shape of the ductwork, there is less friction for the air to move around, so it tends to move faster and more efficiently. This ductwork works great with medium to high-pressure systems. However, due to their round shape, these ducts are usually taller, making them hard to fit in tight spaces.

Rectangular Ductwork

When you see a movie where an action hero crawls through ductwork, it’s usually through rectangular ductwork. Rectangular ductwork is commonly used for tight spaces that round ductwork can’t fit in, like between walls. Round ducts are also easier to connect between fans and main ducts. You may often see more rectangular ductwork in ceilings that have exposed ductwork like warehouses and large big-box stores. 

Rectangular ductwork is also smooth and is great for preventing mold and mildew from being able to grow inside it. However, as air passes through a rectangular duct, it can be very loud. Low-pressure systems are best paired with rectangular ductwork so they don’t have to expand and contract as much with the pressure of moving the air. Rectangular ducts are also more expensive to install than round ducts. 

Ductwork Solutions in Montgomery, Alabama 

So which shape of ductwork is better for your home or business? Ultimately, the answer depends on a number of factors. It’s not uncommon to have a mix-and-match of different shapes and sizes of ductwork throughout your space. Many businesses have rectangular ductwork on the roof, but round ductwork inside. 

The ultimate goal when you have custom ductwork installed in your new building or home is to make sure the space inside is comfortable. An experienced mechanical engineer will be able to build a ductwork system that can efficiently and effectively heat and cool your space so that residents, customers, and staff are comfortable in every season. 

Talk to Hans about Custom Ductwork

If you’re building a new home or business, talk to the experienced mechanical engineering team at Hans Heating and Cooling. We can answer all your ductwork questions and help you find a quality HVAC system to heat and cool your space efficiently. Contact us today to schedule an appointment.

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