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Guide to Understanding the Different Types of Ducts

Guide to Understanding the Different Types of DuctsIn Yuma’s often chilly winters and even more so in our scorching summers, a well-designed air duct system is a big part of what keeps your home comfortable. The types of ducts used in your system influence its efficiency, so it’s helpful to know a little about them.

Sheet Metal

These ducts are made of lengths of sheet metal formed into rectangular or tube shapes. Galvanized steel is most frequently used. Aluminum is reserved for cases where lightweight or custom-shaped ducts are required. Due to their strength and durability, sheet metal ducts are preferred for creating the main trunk line in a duct system. On the downside, these ducts can be noisy when they vibrate or expand and contract with the temperature changes. Connections between two lengths of sheet metal ducts should be secured with screws and sealed with mastic to prevent air leakage.

Fiberglass Ductboard

To make these ducts, fiberglass boards are assembled into a rectangular shape and covered with foil that acts as a vapor barrier to reduce risk of moisture damage. In duct designs that use them, fiberglass ducts are usually chosen for branches that connect the trunk line with the room air registers. Although less expensive, quieter, and easier to install than sheet metal ducts, they’re less durable due to their susceptibility to structural, moisture and mold damage.

Flex Duct

Flexible duct, or flex duct, is made by covering a helix of wire in plastic, insulation, and an outer metallic foil jacket. Thanks to its flexibility, flex duct can be snaked around obstacles and fit through narrow passages. For this reason, it’s favored for use in confined spaces, such as attics. The material is easily damaged and must be installed with care. It’s also less efficient and allows less airflow than other types of ducts, so its use should be limited. If you see long stretches of flex duct in your system, there’s a good change your duct design is inefficient.

For more guidance on how different types of ducts affect your system, contact us at Hansberger Refrigeration and Electric Company in the Yuma area.

Our goal is to help educate our customers in Yuma, Arizona about energy and home comfort issues (specific to HVAC systems). For more information about other HVAC topics, download our free Home Comfort Guide or call us at 928-723-3183.

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