Ducts for Commercial Buildings

Even if you have the best possible HVAC equipment in your building, it won’t help you at all unless you also have the right type of commercial ducts. Ductwork provides the air distribution network that carries heated or cooled air from your HVAC equipment to areas inside your building. Here is a brief rundown of the role of commercial ducts and what types of ductwork is available for installation in commercial systems.

When Commercial Ducts Are Needed

• Initial equipment installation: Commercial ductwork is needed when HVAC equipment is first installed in the new building. During construction, your planners and designers have the opportunity to create a ductwork system that is correctly sized and that fits properly within the physical structure of the building. Newly installed ductwork should also be correctly sealed at the connections to prevent air leaks.
• HVAC system replacement or upgrade: If you are upgrading or replacing the HVAC equipment in your commercial building, it may also be time to replace the ductwork system as well. For example, larger ducts may be needed to increase airflow, or smaller ducts may be required to reduce wasted air and energy. When HVAC equipment is replaced or upgraded, the ductwork system should be thoroughly inspected for damage, broken seals, or other problems.

Common Types of Commercial Ducts

The type of material you choose for your commercial ducts may be influenced by factors such as cost, available space for ductwork, or duct efficiency.

• Sheet metal/stainless steel: Sheet metal ducts are very common. They are usually made of stainless steel sheet metal that has been bent and formed to make rectangular or oval shapes. Galvanized steel or aluminum are also common material used for these ducts. Sheet metal ductwork is sturdy and reliable. It is also easy to connect at the joints and reinforce with mechanical fasteners such as screws if needed. Sheet metal ductwork is also easy to seal at the connections with mastic or metal tape. Metal ducts will usually need to be insulated with fiber board or fiberglass insulation to prevent energy loss. Warm air traveling through insulated metal ducts can easily cool off as it moves. Similarly, cool air can heat up on the way from your cooling equipment to the interior of your building.
• Flexible non-metallic ducts: Flexible ductwork is usually made of a long, continuous length of metal coiled into a spring-type shape. The spring is sheathed with plastic or some type of polymer, creating an unbroken segment of ductwork that can be cut to any length needed. These types of ducts are lightweight and easy to handle, and their flexibility makes them an excellent choice for installation in tight or physically complex areas where straight, rigid ductwork would not be feasible. Keep in mind that the plastic sheathing is going to be much easier to puncture than sheet metal ducts, so duct damage from carelessness or animals could be more common.
• Fiberglass duct board: Fiberglass duct board is made of a layer of highly compressed fiberglass with an outside layer of foil or other material. The foil provides a moisture and air barrier while the compressed fiberglass acts like insulation to keep conditioned air inside the ducts and unaffected by outside temperatures. The internal surface of these ducts are usually lined to prevent any of the fiberglass from breaking off and entering your indoor air. This type of ductwork is inexpensive and relatively easy to install, but it may not give you the type of performance you want. It won’t last as long as other types of ducts and may need to be replaced or repaired more often.