What are air ducts? (2024)

What is air duct?

: a duct or pipe for conveying air (as to the rooms of a house or ship for ventilation or to a furnace)

What is the purpose of air ducts?

The purpose of an air duct network is to guide the air that enters through the air vents to the main heating or cooling component of your central air unit. In addition, the air ducts also help guide air that has been heated or cooled back out of the air vents throughout the home.

How many ducts should a room have?

Generally, the size of your home determines how many vents you will need per room. If your room is larger than 100 square feet, you will need more than one vent (at least two) to really get adequate airflow to the room. If the room is smaller, you only need one.

What is the difference between air vents and air ducts?

Air ducts serve as the pathway for conditioned air, while air vents are the visible outlets that control airflow into the living spaces. Regular maintenance and inspections are essential to detect and address age-related deterioration and potential rodent infestations.

What are the three types of ducts?

There are three common types of duct-flexible, rigid, and semi-rigid. Each type of duct system uses various materials to suit unique applications. All HVAC system installations, repairs, and maintenance should be performed by a trained professional.

Do you need ductwork?

The Importance of Your Ductwork

Your home's ductwork plays a vital role in your air conditioning system's energy efficiency, performance, and durability. The duct system keeps you cool through long hot summers and gives you the blast of warmth when you need it during the winter months.

How many air ducts does a house have?

However, most HVAC contractors use a rule of thumb to determine the number of air vents needed. For example, for a standard residential HVAC unit, you'll generally need one supply vent and one return vent for every 100 to 150 square feet of living space.

Do I need a return air duct in every room?

Instead, there should be at least one return vent in every room, with two or three being ideal. If your house has only one return vent, this is not a problem — make sure to keep the doors open in every room so the air can circulate properly. Make sure there are no furniture, draperies, rugs, etc. blocking return vents.

Where should ducts be placed in a house?

One of the most important things to be aware of when deciding on vent placement in your new home is that typically, air ducts placed near or within the ceiling are the most effective option in terms of energy efficiency.

Where do you put air ducts in a room?

Air Ducts Near the Ceiling Are Most Effective

Many people don't realize this because it is common to see air vents located near the floor in older homes. With vents near the floor, however, furniture often ends up blocking vents and causing the air to get trapped.

How many air ducts do I need?

However, most HVAC contractors use a rule of thumb to determine the number of air vents needed. For example, for a standard residential HVAC unit, you'll generally need one supply vent and one return vent for every 100 to 150 square feet of living space.

How often should you clean your air ducts?

Air ducts, like any other HVAC system, require regular cleaning to ensure maximum efficiency. The National Air Duct Cleaners Association (NADCA) recommends air duct cleaning every three to five years. In some settings, however, the need for commercial air duct cleaning is more immediate.

What are the two types of ductwork?

There are two broad categories of ductwork: flexible and rigid. Flexible ducts are typically round tubes made up of steel wire helixes covered in flexible but durable plastic. Most flexible ducts are also encircled by insulation to keep the air at the temperature it should be.

What kind of duct is best?

Which One Is The Best? Though there are different types of ductwork available in the market today, Sheet metal is most recommended as this type of air duct is non-porous in nature and thus does not allow mold or bacteria to breed in the air ducts.

What is the most common ductwork?

The most common and familiar type are sheet metal air ducts. These are made from either aluminum or galvanized steel. They are durable and relatively easy to install, and their smooth surfaces make them resistant to mold and bacteria growth.

What does an air duct look like?

Galvanized steel or aluminum air ducts can be round, oval, or rectangular like the one Bruce Willis crawls through in Die Hard. Sheet metal HVAC ductwork is the most durable and least likely to harbor mold. Metal air ducts are practically rustproof, especially galvanized steel with its zinc coating.

How long do house ducts last?

Your home's ductwork should last an average of 10–15 years before any significant problems arise. Homes can experience pest infestations, cracks, and collapsed ducts if repairs are not made on time.

Can you have central air without ductwork?

A ductless central air system doesn't use ducts. Instead, it uses a network of pipes to move the air around. These pipes work like a network of tubes. They're connected to each other and to the heating and cooling units.

How often should ducts be replaced?

To prevent these problems, you need to replace your ductwork after every 10 years. This way, you will ensure that the air ducts remain in good condition to provide high air quality indoors. In some cases, air ducts may begin malfunctioning even before they get to the end of their lifespan.

Do bedrooms need cold air returns?

Does Every Room Need Air Return Grilles? While it is a myth that air return grilles are required in each and every room in the house, it is definitely necessary to have more than one of these grilles installed at strategic places in the house. The most important place to have these would be the bedroom.

Is replacing air ducts expensive?

On average, replacing ductwork costs $10 to $40 per linear foot. This includes materials and labor, including the removal of pre-existing ductwork components.

What is the most commonly used ductwork in an HVAC residential system?

Sheet Metal Air Ducts

By far the most common type of rigid air duct material found in today's homes is sheet metal, which typically refers to either galvanized steel or aluminum metal. They typically come in various shapes: Round, rectangular, or even in a spiral oval shape in some situations.

What happens if you don't have enough return air?

If there's not enough return air, your living room can be 10℉+ warmer or cooler than, for example, the bedrooms. Not enough return air in summer can cause rooms close to the central unit to be cooler and those farther from it to be warmer. In winter, rooms farther from the furnace can be too cool.

Which rooms need cold air return?

Does Every Room Need Air Return Grilles? While it is a myth that air return grilles are required in each and every room in the house, it is definitely necessary to have more than one of these grilles installed at strategic places in the house. The most important place to have these would be the bedroom.

Where is the best place to put return air ducts?

Return registers can be large and centrally located in your home, or they can be in every room. HVAC professionals recommend that each room have a cold air return vent to help with flow and temperature control. These vents are typically found on an interior wall.

What room should return air ducts not be installed?

Return air shall not be taken from a closet, bathroom, toilet room, kitchen, garage, mechanical room, boiler room, furnace room or unconditioned attic.

What is the two foot rule for ductwork?

The air now has to re-pressurize to regain its turbulent flow so it can continue to push its way down the duct. It requires about 24′ or two feet to do this. This is the 'Two-Foot Rule?. Ideally, you should allow at least 24′ between takeoffs and at the end of any duct run.

What is the most common duct system layout for a house?

Another essential decision that needs to be made is the basic configuration of the supply duct system. There are at least four basic supply duct system designs: spider, radial, perimeter loop, and trunk and branch. The radial and trunk and branch are the ones most often used in residential HVAC.

How do I find air ducts in my house?

Your air ducts will be located within the framing of your home. They can be within floors, ceilings, or walls. If your vents are located on the floor, you will find your ducts in the flooring. If your vents are on the ceiling, your ducts are in the ceiling or walls.

How long do air ducts last?

Your home's ductwork should last an average of 10–15 years before any significant problems arise. Homes can experience pest infestations, cracks, and collapsed ducts if repairs are not made on time.