What Are The Main Components of Residential Ductwork?

What Are The Main Components of Residential Ductwork?Many homeowners are great at being proactive about HVAC maintenance. But a smaller percentage understand their residential ductwork and the impact that it has on their home’s heating and cooling systems.

This article will help with that. It covers the ins and outs of residential ductwork to help you gain a better understanding of how your home is climatized. Keep reading to learn more.

What is an Air Duct?

Air ducts are conduits that spread warm and cool air throughout your home. They feed air into the HVAC system so that it can be climatized and then disburse it evenly throughout the home.

If you’ve ever put your hand up to a vent and felt air blowing out of it, that air had to complete a journey through your residential ductwork to reach you.

Types of Air Ducts

Sheet Metal

Sheet metal air ducts are highly durable and very resistant to mold formation. It’s also difficult for them to accumulate rust – especially when your home has sheet metal air ducts that are made out of galvanized steel and zinc coating.


Flexible air ducts are very adaptable to tight spaces. They’re a good fit in tight, bendy locations where rigid sheet metal air ducts won’t fit.

These air ducts are often made from a steel wire spiral that’s been wrapped with bendable plastic and surrounded by insulation.


Fiberboard air ducts are made out of compressed fiberglass fibers, which have a sealant applied to them to ensure that no air leaks out from them. These are rigid, like sheet metal air ducts, but are less expensive because they’re made out of lower-cost materials.

Although these are cost-effective, they’re also prone to mild and mildew. So if you have fiberboard ducts in your home, you may need to take special care to keep them clean.

How Air Flows in a Forced Air Duct System

Air flows through your HVAC system in a cycle that looks something like this:

  • Return vents suck air in from your home
  • This air gets transported, through ducts, to your central air conditioner or furnace
  • The air is warmed or cooled based on the setting of your thermostat
  • This newly-climatized air gets sent back through the ductwork
  • Supply vents distribute the climatized air throughout your home

Signs Your Ductwork is Bad

Uneven heating and cooling

This is the clearest sign that some of your ductwork may not be working properly. You might have a leak or another issue that’s interfering with airflow to a particular room. Calling an HVAC technician is the best way to pinpoint the source of the problem.

Missing air flow on supply vents

The next time you have your heating or cooling running, place your hand or a piece of paper up to a supply vent and see if you notice any airflow. If you don’t, that’s a clear sign that something is happening in your ductwork.

Unexplained high utility bills

If your utility bills suddenly increase dramatically, it could be a sign that you’re losing up to 30% of the air that’s sent through your ductwork. When this happens, the system has to work harder to achieve the same heating or cooling levels in your home.

Loud noises

Finally, loud noises can also be a sign that your ductwork has an issue. Rattling, whistling, and banging can all point to loose, disconnected, or outright damaged ductwork.

Indoor Air Quality Can Help You Take Care of Your Residential Ductwork

If you think that you may have a problem with your residential ductwork, Indoor Air Quality is here to help. Our team serves Highlands Ranch and the entire Denver Metro Area and would be happy to come out to your home, analyze your problems, and come up with a solution to them.

Get in touch with us today to learn more about how we can help.