Everything You Need to Know About Your Ductwork

Ductwork refers to the system of ducts (metal or synthetic tubes) used to transport air from heating, ventilation and air-conditioning (HVAC) equipment throughout your home. Properly installed and well-maintained air ducts are a key component of indoor air quality and home comfort.

In HVAC systems, air moves through a continuous cycle that extracts air from inside the home through return ducts. The air passes through a filter to collect contaminants and is then heated and cooled and sent back throughout your home through supply ducts until it’s cycled again.

Main Components of Your Ductwork

Pipes and trunks make up the majority of your ductwork, which connect to the HVAC unit and distribute the air throughout your home. The trunk is usually the largest component that connects to your unit and the pipes, which distribute the air to individual rooms.

Transitions help connect duct pipes and trunks together. Take-offs, turning vanes, cleats, specialized connectors and angled boots create pathways for air to travel effectively throughout your ductwork.

A plenum is an air distribution box that brings in and distributes air from the main supply fan to the individual rooms in your home. It is essential in regulating the air temperature and quality by removing pollutants from the air before being distributed. There are two plenums within your ductwork:

The supply plenum connects to your AC, heat pump or furnace and pushes the newly conditioned air to the ducts.

The return plenum collects air from the return vents and distributes it to your heating and cooling unit to be cooled and heated again.

Flues distribute air outside and help keep you safe from toxic fumes that are produced during heating and cooling. They carry the exhaust from the ducts outside to improve your air quality.

The air handler is attached to the duct system that contains the blower fan, dampers, air filter and heating and cooling elements. The blower fan moves the air through the ducts once the air is at the proper temperature.

Drain pans and drain lines help remove excess moisture and prevent mold from growing in your ductwork.

Refrigerant lines connect the indoor and outdoor units together to allow refrigerant to flow.

Different Types of Ductwork

Sheet Metal
These ducts are made of galvanized steel or aluminum that can be round, oval or rectangular. They are the most durable and rustproof (mainly galvanized steel because of its zinc coating) and are less likely to harbor mold. Sheet metal ducts are easy to clean, maintain and repair, and aren’t affected by extreme temperatures. Labor costs for installation run higher than other duct types.

Flexible
Flexible ducts are made with a polymer (bendable plastic) with round wire coils inside. Lightweight and cost-effective, they are commonly used to branch off the main HVAC system to deliver air to different rooms in your home and work well in tricky spaces. Correct installation prevents flexible air ducts from sagging over time. These ducts can be more prone to punctures and kinks.

Fiberglass Lined
Fiberglass ducts are similar to sheet metal ducts with the addition of a fiberglass lining to help reduce heat loss. Proper maintenance and regular cleaning are required to prevent the seal from wearing down, which can occur from extreme temperature changes. Fiberglass ducts are often used in office and commercial buildings as it helps to dampen the sound of the HVAC system.

Fiberboard
Fiberboard air ducts are typically the least expensive, prevent noise and come pre-insulated. However, their rough fiberglass surface can slow airflow efficiency. They are comprised of resin-bonded fiberglass encased in foil to create a barrier against air and water vapor.

Signs Your Ductwork isn't Working Properly

Hot and Cold Spots
Uneven heating and cooling in your home can mean little to no airflow is reaching certain rooms. It could mean there is a blockage or disconnected ducts preventing the air from reaching the vents.

Loud Noises
Unusual noises like rattling, banging, or whistling could mean you may have disconnected or damaged air ducts. There could also be debris or objects within the ducts causing the disruption.

Low Indoor Air Quality
Your air quality could be poor if you see more dust buildup than normal in your home or if your allergy symptoms start to flare up. Smelling a musty odor could be signs of mold or mildew within your ducts.

Dirty Ducts or Vent Covers
If you see a lot of dust or debris on your vent covers, it could mean there is a lot of dust in your air ducts. Regular maintenance can avoid this problem. Changing air filters every three months and cleaning your air ducts (every 2-5 years) can help keep your utility bills down.

Signs of Rodents or Insects
Sometimes rodents and insects can make their way into your air ducts, which can cause a lot of problems. If you hear strange sounds like running or chewing, look at your ducts and see if you notice any rips, holes, droppings, or signs of insects. 

Benefits of Ductwork Cleaning/Maintenance

Clean ductwork does a great job of distributing heated and cooled air. It will improve your air quality, reduce unwanted odors, increase energy efficiency and extend the life of your HVAC system.

Home heating systems produce a small amount of carbon monoxide, a harmful gas that is normally transferred outdoors through your ductwork. If pipes and vents are clogged or obstructed, that gas could find its way into your home’s air and compromise your family’s health.

Fortunately, simple routine ductwork maintenance can prevent any potential carbon monoxide leaks. A qualified service technician can perform a thorough inspection of your heating system and ensure all ducts are clean and unobstructed. And by scheduling preventative maintenance each year, you’ll also help keep your equipment operating at peak efficiency and avoid any emergency repairs later.

Healthy Climate® ventilation systems not only make your home feel less stuffy, but they also expel allergy-aggravating pollutants along with stale indoor air. And since they transfer moisture and energy from outgoing air to the incoming fresh air, ventilators help reduce heating and cooling costs and keep humidity levels in check.

To learn more about your options or schedule an appointment, contact your local Lennox Dealer.