It is generally best to choose tubular rigid metal duct tubing for as much of the duct run as possible. This type provides the greatest air volume and offers few, if any, inner obstructions to catch flammable lint.
Ideally you want rigid metal duct. Having less change of crimping and bending means less chance of lint buildup, which means less chance of fire hazard.
Rigid Metal Ducting: Rigid metal ducting, such as aluminum or galvanized steel, is widely considered the gold standard for dryer vent systems. These materials are non-combustible and can withstand high temperatures, reducing the risk of fires.
Rigid ducts are made from galvanized steel or aluminum. They can be either rectangular or cylindrical in shape. Rigid ducts are more durable than flexible ducts and can withstand extreme temperatures.
1 Answer 1 The best choice is metal hard wall duct. It is smooth inside and does not cause lint to build up. Lint build up can be a bit of a fire hazard and leads to restriction of air flow that is exhausting moisture. That leads to extended drying times.
The dryer vent is normally installed by the contractor that does your HVAC work (ducts etc.) The exhaust fan requires an electrical connection and ductwork. The electrician will run the wiring and provide the switch.
How Long Should A Dryer Vent Be? A dryer vent should not exceed 35 feet in length. Furthermore, for every 45 degree turn of a dryer vent you should remove 2.5 feet in total allotted length. For every 90 degree turn, you should remove 5 feet in total allotted length.
Disadvantages of Flex Duct
Flexible ducts are more prone to air leakage around the seams, which can lead to lower HVAC system performance. Additionally, the pliable nature of flex duct tends to make them prone to tangling or crushing when they pass through tight spaces or fixtures.
The longevity of HVAC flex ductwork hinges on several key factors, including material quality, installation, and maintenance. Typically, well-installed and properly maintained flex ductwork can endure for 15 to 25 years.
Sheet metal ductwork is the most common type because it's tough and long-lasting. Plus, it has a smooth surface for easy cleaning.
Per the requirements of the International Residential Code, Section M1502 (2009-2021 IRC), the clothes dryer exhaust duct should be a rigid or semi-rigid metal duct made of galvanized steel or galvanized aluminum with a smooth interior finish and a duct diameter of 4 inches.
A refrigerated non-cycling dryer is an excellent cost-effective choice for anyone looking to improve their compressed air quality. The term "non-cycling" means this type of dryer constantly operates refrigeration. It also utilizes a hot bypass valve to redirect the coolant, even at a less than full load condition.
Vent Type and Length
Any Dryer ducting used must be UL-listed. UL now requires that all Dryers be installed with either rigid or flexible metal ducting. Rigid is preferred. A UL-listed semi-rigid Dryer duct can be used if the vent length is 8 feet or less.
Dryer venting tips and practices
Flexible transition hose between the dryer and the wall outlet should be either the foil type or the aluminum flexible duct (most preferred). Do not use the plastic or vinyl. Concealed ducting must be rigid metal (galvanized or aluminum) duct.
M1502.
Flexible transition ducts used to connect the dryer to the exhaust duct system shall be limited to single lengths not to exceed 8 feet, and shall be listed and labeled in accordance with UL 2158A.
Dryer vent installation or replacement cost
New dryer vent installation costs $200 to $800 on average to add ducting through an exterior wall. A dryer vent replacement costs $100 to $300. Indoor dryer-duct installation costs $65 to $120 if allowed by building code. A dryer vent hose costs $10 to $30 for materials.
Rigid ducting is quieter than its flexible counterpart. Due to its shape, sound waves are smoothly channeled and directed by the material. On the other hand, flexible ductwork is often noisy as its walls expand and contract due to air pressure and temperature changes.
Sheet metal ductwork: The most common type available, sheet metal ductwork is used for a range of structures and lasts roughly 20 to 30 years. Fiberglass: This rigid form of ductwork is used to meet specific space needs and is designed to provide a high thermal performance. It lasts around 15 to 20 years.
Unlike rigid metal ducts, it can easily bend around obstacles and fit into challenging spaces, making it a popular choice in homes where traditional channels might be difficult to install. These flexible channels aren't installed where they'll be visible. Instead, it's placed in attics, crawl spaces and roofs.
However, due to its thin material, flexible ductwork is more likely to become damaged due to crushing or tearing. It may require replacement after 10-20 years. Fiberglass ductwork has become less common due to concerns about its potential to deteriorate and release fiberglass particles into the air.
Despite the higher cost, sheet metal has numerous advantages over the other types of ductwork that typically make it the best option. Sheet metal ducts are extremely durable, as the metal used to build the ducts is fairly thick. This makes sheet metal ducts less prone to damage and leaks compared to the other options.
While there are older versions of the material that may not be able to withstand the process and need to be replaced due to already existing damage, but most flex ducts are made with a metal spiral support to allow for contact vacuuming and other cleaning methods.
Better Airflow: One of the primary benefits of using a hard pipe for dryer venting is that it provides better airflow. The smooth interior of a hard pipe allows air to flow freely, while the ridges and creases in flexible accordion piping can cause restrictions in airflow.