We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What are the Different Type of Duct Supplies?

By S. Waddell
Updated May 17, 2024
Our promise to you
About Mechanics is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At About Mechanics, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject-matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

Heating and air conditioning ductwork installation requires a number of duct supplies. These duct supplies are most commonly made of sheet metal. The main trunk line is rectangular duct and is joined together with slips and drives. Hangers on the duct can be made from 1-inch (2.54-cm) strips of sheet metal. A plenum is a fitting used to connect this main trunk line to the furnace.

The main supply duct trunk line will have smaller branch supply trunks coming off of it. These branches will deliver the air to each register opening. Branches are usually rigid, round pipe, but they can also be made of flexible fiberglass duct. They are connected to the main trunk line with a takeoff.

A takeoff can be rectangular or round and fits into a hole cut into the ductwork. It has tabs on the end that are to be bent over inside the duct. This holds the takeoff securely in the duct. When using flex duct, it is necessary to use nylon duct straps to secure the duct to the takeoff.

The branch supply trunk lines will run to each of the register openings. Elbows or offsets may be necessary to get the duct to line up in the right spot or to avoid obstacles in its path, and it is sometimes necessary to use a reducer to change the round duct to a smaller size duct. A wye can be used to supply air from one branch duct to two openings. A tee cap closes off the end of a piece of round pipe. A register boot is nailed into the opening and the branch duct will attach to that; the register is then put into the boot.

The return air duct uses the same sheet metal duct supplies. Sometimes, in an effort to cut costs, ductwork is not used for all of the return air; panning is used instead. Panning material is either sheet metal or some type of foil-faced cardboard that is installed over the joist space and the stud space. This creates a tunnel for the passage of return air. A return air elbow is usually used to join the return air duct to the furnace.

Other duct supplies may be necessary to achieve a balanced heating and cooling system. Manual or electronic dampers can be put in the duct to regulate the air flow. All joints should be sealed with a special duct mastic or adhesive. A special aluminum tape also works well, but do not use duct tape. The ductwork should be sealed as it is assembled.

About Mechanics is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Discussion Comments
About Mechanics, in your inbox

Our latest articles, guides, and more, delivered daily.

About Mechanics, in your inbox

Our latest articles, guides, and more, delivered daily.