What Kind of Duct Work Do I Need to Hook Up a Central Heat & Air Unit to My House?

Round Metal Pipe

• Round metal pipes are a common type of duct work you can use with your heating and cooling system. They are used as main trunk lines as well as branch lines to your registers. They are efficient in carrying air and are long-lasting. They usually need to be 8 inches in diameter for heating and cooling systems. A heat only system might only require 6-inch sections. They come in lengths and are factory crimped on one end so that they fit easily into another section of pipe. They might need to be insulated in some cases.

Rectangular Duct

• Rectangular ducts are often used because they can easily fit between floor studs and can go in many places where rounded ducts cannot. They are also long lasting and are generally made of 30-gauge galvanized sheet metal. Rectangular duct work is generally only used as a main trunk line and is rarely used as a branch pipe to run to your various room registers. Round pipe is also used in combination with rectangular duct. They also need to be insulated in many instances.

Insulated Flexible Duct

• Insulated flexible duct work has some advantages that include the ability to fit the pipe into various forms to fit most places you might need it. It is also easily installed and can reduce your labor costs dramatically. You likely won't need as many fittings for turns in the duct work because it is flexible, and it comes pre-insulated. On the downside, the flexible ducts do not provide as good an airflow as the other types and don't last nearly as long as other metal ductwork.

Mini-Ducts

• If you have a multi-level home with a finished basement or attic, installing duct work in the home can be challenging because it will be harder to hide. The use of mini-ducts comes in handy for these purposes. These 2-inch plastic ducts provide adequate airflow through small pipes that can be threaded through walls and in ceilings or floors. Installation might be more expensive as a result of using minis because they require many more outlets than other types.