Ductwork is the part of the HVAC system. High quality ducting is essential to the effective running of a ventilation system. When ducting is selected and installed correctly, it can improve and prolong the efficiency of the whole system, leading to long term low maintenance.
There are two broad categories of ductwork: flexible and rigid.
What is Rigid Ducting?
Rigid ducts can be different sizes and made from different materials, and they can be either rectangular or cylindrical. Because the ducts are rigid, they do not have the risk of kinks or bends restricting airflow and, unlike flexible ducts, they cannot be torn or punctured. However, rigid ducts cannot be easily used in tricky spaces.
There are three main types of rigid ductwork: sheet metal ducts, fiberglass lined ducts, and fiberboard ducts.
Made from compressed fiberglass strands which are bonded with resin, and covered with a foil laminate for moisture protection.
Fibreglass-lined ducts are sheet metal ducts that have been lined with fibreglass for sound insulation. The fibreglass is sealed so that it cannot make its way into the air stream.
Sheet Metal Ducting
The most common materials used for sheet metal ducts are aluminum and galvanized steel.
What is Flexible Ducting?
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.
Using this kind of ducting is best in tricky spaces where rigid ducts are not just possible to install. They are also used to install ductwork which is not flexible to a certain air supply outlet. Flexible ductwork uses cheaper materials and therefore is a cheaper option.
Pros and Cons
Because metal ducting lasts longer than flex duct, it's more costly to create, transport, and install.
Flex ducts are better for existing trunk-and-branch heating and cooling systems. This is because they're more versatile and flexible. Metal ducts are more rigid due to the nature of steel.
In comparison to metal duct, flex duct is easier and faster to install.
The job of ductwork is to direct air coming out of your HVAC unit, and distribute it to different spaces in your home. Simply put, without ducts, every room of your home would be a different temperature.
Choosing the right ductwork for your home comes down to the overall design, your needs for heat retention or noise reduction, and budget.