Industry Articles From Kaempf and Harris

The Difference Between Residential And Commercial Ductwork


While a residential and commercial heating and cooling system have similar components and are made to perform the same function, a slight difference between the two exists. It starts with the ductwork.

Check out Kaempf & Harris’ breakdown of residential and commercial ductwork:  

Material. According to Sobieski Services, a commercial and residential HVAC and plumbing company in Wilmington, Delaware, commercial ductwork is usually made from one of the following:

  • Stainless steel constructs of shaped sheets and are usually either round or rectangular. Metal ductwork is installed in large sections with smaller sections making up the occasionally adjustable elbow joints where the duct must bend. Stainless steel ducts help prevent air leaks.
  • Flexible non-metallic ducts are very light and easy to bend because they’re made of a continuous length of metal spring sheathed in plastic or similar nonmetallic substance. They’re useful in areas where larger metal ductwork isn't practical due to limited space or an unusual pattern with or without obstacles.
  • Fiberglass duct board is made of compressed fiberglass with an external foil layer that resists moisture and provides an air barrier. Their smooth interior offers limited airflow resistance, and they’re frequently lined to prevent any fragments of fiberglass from coming loose.

Maintenance. Generally, the cost for upkeep of a building’s HVAC ductwork cleaning is higher due to the complexity of the system and the extensive training of a commercial technician.

However, the same gas-powered vacuums are used for residential and commercial duct cleaning jobs.

Location. A major difference between residential and commercial units is where they’re located in a home and business, respectively. Residential HVAC systems typically reside on the ground near the home, while commercial HVAC systems are located on the roof due to the following reasons:

  • Their large size
  • The ability for technicians to perform maintenance without disturbing everyday occupants or scheduling
  • Protection from vandalism
  • Safety from interference in parking lots and on sidewalks

Components. Residential and commercial metal ductwork are both inside. However, residential HVAC systems are usually in splits, an industry term that means two units work together to heat and cool the home. The indoor unit houses the blower, evaporator, and condensate drain, while the outdoor unit houses the compressor, condenser, and condenser fan.

Commercial HVAC systems are usually one unit with those components in a single cabinet that remains outside. Zone dampers are housed inside the building with the metal ductwork.

Additions. Residential units are typically standalone and can’t be built upon. Because the indoor and outdoor units need to work together, the entire system needs to be replaced if any significant changes to the heating and cooling system are required. This includes any change to metal ductwork like zoned heating and cooling.

Commercial units are modular, which means that they can be altered as needed. Technicians can also add onto modular commercial units and can transport smaller components of this large unit more easily than the total residential unit. However, the commercial ductwork is not often changed.

Complexity. Commercial units are more complex and detailed than their residential counterparts. Buildings often use a trunk-and-branch ductwork design because they’re made from fiberglass duct board, which costs the least amount of money.

This ductwork is larger because it’s made to heat and cool a larger indoor area with more occupants. As a result, the drainage system also needs to be bigger and more windows for exhaust are required.

Residential units have smaller ductwork systems (usually in the attic or basement), only one drainage pan, and a few windows to alleviate exhaust.  

For more information about commercial ductwork design, download Kaempf & Harris’ Cheat Sheet To Ductwork Terminology by clicking on the button below:

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Topics: Sheet Metal Fabrication

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