All You Need to Know About HVAC Ductwork

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If you are about to start a construction or remodeling project, you need to know some essential aspects.

Ductwork is one of the phases of construction that people tend to neglect.

For example, expanding or adding a room can significantly affect the ductwork.

It may influence the heating and cooling systems of your house or office as well.

Even the addition of a small-sized room can have an impact on ductwork.

It’s significant to do the job right, otherwise, the consequences can be unfortunate.

For this, you need to understand what ductwork is, what are its components, and how to operate it correctly.

After getting more information about the ductwork systems and process, you can be sure that all your projects go smoothly.

In the guide below, you will find the necessary information that will help you better understand the HVAC ductwork.

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Fundamentals of the Ductwork

Ductwork is a system that circulates airflow from the HVAC systems to your house or office.

The air is absorbed by the air conditioning or heating system from your building.

Then after it is cooled or heated, it’s pushed back into your dwelling-space through the ducts.

The indrawal and release of the air depend on the efficiency of the duct system.

If your return vents are designed poorly, the balance of the heating and cooling systems and air load will be flawed.

It will negatively affect your climate control system and home efficiency.

There is a difference between ductwork and the pipes transferring refrigerant, water, or gas.

Ductwork is used only for the air.

Ductwork systems can be designed in different shapes and constructions.

They can be round, oval, or rectangular.

A variety of materials can be used for ductwork manufacture such as fiberglass, plastic, metal, etc.

Some type of duct system is usually installed in the majority of the houses with traditional heating and cooling system.

It can be central air conditioning, central heating, forced-air heat, and more.

Is Ductwork Still in Use?

Previously, traditional heating and cooling ductwork systems were superior in the home ventilation area.

However, now they are facing some major challenges for the first time.

Split-system air conditioner and heat pumps use zoning strategies.

It makes a building more energy-efficient.

These systems don’t use standard ductwork either.

At the moment, the HVAC industry focuses greatly on ductless heat pumps and air conditioning.

Before undertaking your construction project, you should consult an expert to find out if these systems are advisable for your building.

Ductless systems will require some additional steps to ensure adequate ventilation of your house or office.

Enhanced ventilation can become a problem for those who replace their windows or insulation.

Usually, this issue doesn’t require extensive repair, but the HVAC expert will have to evaluate it to handle it properly.

Minor alterations in your ductwork system can greatly improve the comfort and energy efficiency of your dwellings.

The System Should Be Installed Properly

Properly-installed ductwork system is a key to comfort in your home.

It controls the temperature of the entire house efficiently.

The poorly installed system, on the other hand, can raise a number of problems.

Junctures between the duct components are sealed up with aluminum tape.

The ductwork itself is insulated from crawl floors or attics.

Unless these two matters are dealt with properly, there can appear an air leakage.

In this case, the system loses its efficiency and lowers air quality.

It can also cause a break down of the AC or heating systems and may lead to heavy expenses.

The size of the ductwork system is another significant factor to take into account during the installation.

The ductwork and the size of the heater or air conditioner should match to ensure performance efficiency.

The ductwork installers should match the duct system and your HVAC equipment perfectly.

The experts also adjust the duct systems for better comfort, durability, and efficiency.

The process is called balancing.

It includes the adjustment of the dampers in the duct to flow the right amount of air to every room.

Reasons to Keep Ductwork Clean

The air quality in your dwelling is imperative.

Keeping the air clean from dust, pollen, allergens, etc., includes more than only timely air filter change.

The pollutants can accumulate in your ducts, so regular cleaning is a necessity.

Cleaning your air duct on a regular basis can help improve the health of the tenants and keep the premises clean.

Below, a few reasons for keeping the ducts clean are listed:

  • Mold.

Mold can be extremely harmful to your health.

It can cause such health issues as allergies or even asthma.

If you smell an odor resembling dirty socks, it can be a sign of mold in your HVAC system.

  • Clogged ducts.

Due to dust and other pollutants, your ducts can get clogged.

It can lower the efficiency of your HVAC system and lead to some health concerns.

  • Decreased efficiency.

If the air ducts are clogged, maintaining the right temperature in the premises can become harder.

As a result, your system will be inefficient and the utility bills, higher.

What Ductwork Is Made Of

A variety of materials can be used for ductwork manufacture, which include:

  • Galvanized steel.

Galvanized steel is one of the most common materials used for ductwork.

The metal contains zinc coating which prevents it from rusting.

It can help you avoid potential painting expenses.

The ducts are fixated with the help of fiberglass blankets or duct wrap on the outside.

If applicable, they can be lined with a double-walled duct.

  • Aluminum.

The ductwork manufactured of aluminum is light and easily installed.

If it is required for your system, you can get the ducts custom-made in the shop or at the worksite.

Aluminum ducts are not too popular though in comparison to galvanized steel.

  • Fiberglass.

The fiberglass ducts provide a higher level of in-built insulation.

Its inner side can soak up sound, so the operations of a cooling or heating system will be quieter.

  • Flex ducts.

Flexible ductwork is manufactured of metal wire coil covered with flexible plastic to form a tube.

The ducts can be configured in many ways.

They are perfect to be attached to the vents supplying air to the inflexible ducts.

Components of Ductwork System

Apart from ducts, a ductwork system includes other components.

They are essential to make the system operate properly and provide a high quality of air.

Below, some of the main ductwork system components are listed:

  • Vibration isolators.

Vibration isolators are flexible units installed in the duct.

They are usually situated before or after the air handler.

These units minimize the vibration when the duct system is working.

The air handlers are installed at the beginning of the duct and include blowers.

Blowers produce the vibration, which is spread throughout the building by the duct system together with noise.

The vibration isolators made with rubber material suppress the vibration.

  • Take-offs.

Take-offs are situated in the main duct wall fitted into the openings.

Small portions of the flow travel from the branch ducts to the main one through them.

Multiple metal tabs attach them to the main duct.

  • Stack boots and heads.

Ducts, a.k.a. stacks, transport the airflow in thin walls vertically.

They are formed with thin or wide oval or rectangular sections.

A stack boot is situated at the bottom of it.

It transits the air from the regular duct to the one mounted in a thin wall.

A head stack circulates air back to the regular duct on the top.

  • Volume control dampers.

A duct system needs to push different volume of air to various sections.

Volume control dampers are responsible for this.

They can be automatic or manual.

Zone dampers provide automatic control in basic systems.

Variable air volume (VAR) controls more complicated systems.

  • Smoke and fire dampers.

These parts are mounted in the system and trigger if a duct is surrounded by fire.

If they detect smoke, the duct will be sealed immediately.

Later, they can be reopened only manually by a technician.

  • Turning vanes.

Turning vanes are a part of ductwork that reduces turbulence and resistance of the airflow.

The vanes guide the air and make it change direction.

  • Plenums.

An HVAC system includes central collection and distribution units.

The return plenums transfer air from return vents to the air handler.

The supply plenums, transfer the airflow from the central unit to the rooms for heating or cooling.

  • Terminal units.

Terminal units are installed in the branch ducts.

They are usually used in multi-zone HVAC systems.

Only one terminal unit is normally installed in each thermal zone.

They come in the form of VAV boxes, induction terminal units, or fan-powered mixing boxes.

Some of them may include heating or cooling spirals.

  • Air terminals.

These vents supply air or can serve as the exhaust or air return channel.

In smaller residential HVAC systems, diffusers usually supply air.

Exhaust air terminals sometimes contain the air filter but are mostly used for appearance.


Efficient duct systems are essential for a good quality of air in your dwellings.

Proper installation is the main factor and should always be performed by a trained professional.

They should be able to understand and assess your requirements and ensure the efficient work of the system.

It is essential to clean and maintain your system regularly to ensure the quality of air in your dwellings.

Cleaning is done the best by professionals.

There is a variety of materials you can choose for your ductwork.

However, it is advisable to consult with an expert to get the right option.

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