Flexible Air Ducts

Pros	Cons
Affordable	Easily compressed
Easy to install	Prone to sagging
Better for going about bends	Ridged inner surface affects airflow
Quieter than rigid metallic	Less durable than canvas metal
Already insulated	Hard to clean
	Cannot be used for dryers or range hoods

Flexible air ducts are affordable, slowly to install as well as bend, quieter, too oftentimes pre-insulated. They are, still, as well easily compressed, prone to sagging, ridged on the within (affects airflow), less durable, difficult to clean, as well as disallowed for role alongside dryers and range hoods.

Pros of Flexible Air Ducts

Affordable

One of the advantages of flexible air ducts is that you tin can wait the price to be relatively cheaper than the alternative (rigid ducting).

The material are cheaper as well as cheaper to industry. Furthermore, the flexibility in addition to lightweight characteristics hateful that they are less problematic to install, ask less specialized gear, and less time. All of this contributes to a more affordable installation toll.

Flexible ducts are made from flexible polyester or aluminum. For the flexible polyester, yous can expect a toll that ranges from $one to $iv per linear foot. The flexible aluminum is simply slightly more expensive at, on average, $2 to $v per linear human foot.

So, spell the cost volition differ betwixt the material, but you should live able to position flexible ductwork for well-nigh $10-$25 per pes, including installation costs.

In comparison, the option, which is stiff ducting typically made from stainless or galvanized steel, price well-nigh $5-$xx for the cloth and upwards to $65 for the materials too installation.

Easy to Install

As mentioned briefly, flexible air ducts are tardily to install, particularly when compared to rigid ductwork. Unlike stiff ductwork, which virtually e'er involves cutting, fastening, as well as sealing shorter ductwork runs, flexible ducts can essentially only live set out.

The installation of rigid ductwork also requires much more than planning and attention to particular. Once a rigid duct is installed, it’s nigh probable non going to be moved or changed anytime shortly. Flexible ductwork on the other hand tin live moved together with manipulated every bit needed.

Another reward to installing flexible ductwork equally opposed to stiff ductwork is the issue of tools needed for the job.

While rigid ductwork would telephone call for tin snips, hammers, saber saws, and sheet metallic screws, flexible ductwork tin live cut alongside pair of scissors or knife together with connected amongst duct tape (marked “181B-FX) or mastic (marked “181B-chiliad”).

With that existence said, installing flexible ducting becomes a much more than viable DIY projection whereas rigid ducting should ideally live installed by a professional person technician.

tools needed for installing flexible ducts and rigid ducts

Better for Going Around Bends

As you lot would in all probability imagine judging solely by its cite, flexible ducting is much easier to maneuver about bends than rigid ducting.

Referring back to the installation procedure, this is where flexible ducting can salve yous quite a chip of time. While cornering amongst sail metal requires precision cut as well as attachment of elbows, flexible ducting tin but live bent.

It tin besides live slights curved to become around an obstacle, something that would live hard with a stiff textile.

However, y'all should greenback that you cannot just twist together with curve your flexible ducting amongst abandon. A slight bend may make no departure, just a bend is equivalent to an elbow, affecting airflow too shortening the allowable ducting length.

Quieter Than Rigid Metal

A ventilation duct is not still. The campaign of air through the duct rattles the arrangement. Sometimes, the racket is indicative of a job, simply around racket is definitely to be expected.

Because at that place is close to pass on in addition to stretch to a flexible duct, it tin answer to the pressure level of the air flowing through it in such a mode every bit to absorb approximately of the affect exerted on it too cut down the dissonance of the airflow.

Already Insulated

Flexible air ducts are useful in tight, cramped areas of the house such every bit attics as well as crawl spaces. These are frequently areas that are unconditioned. If yous leave the ventilation arrangement uninsulated, and then H2O tin can offset to drip from your vents every bit a consequence of condensation (hot pipes contacting cold air or vice versa) as well as yous volition as well non be running the almost energy-efficient system.

Rigid ducting about often requires sort out insulation, whereas flexible ducts most frequently come up alongside a layer of insulation when y'all purchase them _{^{(amazon link)}}. Even if they are not insulated, they are easier to insulate.

Take a Detour

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Cons of Flexible Air Ducts

Easily Compressed

The flexibility of these ducts gives them not bad qualities as well as abilities that we take already looked at, but there are some drawbacks too. The more than flexible a material is, the easier it is to mash or compress.

This can live helpful when yous are trying to squash it past an obstacle too into the right position, just it should be able to render to its original form in one case in place. If it is shoved into a spot that permanently compresses it, the airflow will live restricted.

Man in gray shirt fixing and compressing flexible duct

This type of compression is a user pick (one.e., it is possible fifty-fifty though it is undesirable). With rigid ducting, at that place is no temptation to endeavour because it is impossible to crush the canvas metal into these spots.

Then at that place is as well the unchosen kinds of compression. If something falls against your flexible duct, and so it tin can be squashed. Airflow is negatively affected and the adventure of the duct existence damaged or even compromised is high.

Prone to Sagging

Another result with the flexibility of these ducts is a tendency to sag. Pulling the flexible duct to its full length will help mitigate this job, simply it cannot eliminate it altogether.

Ducting oft needs to be suspended across beams and in that location will be portions unsupported past the family’s framework. With stiff metallic, this is non an result; the ducts concord their ain weight. Flexible ducting will sag if not supported sufficiently.

Gravity does this, only it is exacerbated past the stretching caused past the pressure level of airflow through the vent. The collection of H2O in the ducts volition also weigh portions of the duct downwards.

When suspending a flexible duct, be certain to provide it with the proper supports in addition to break equipment. Each back up should be inside iv feet of each other alongside additional suspensions before together with afterward a curve. Keep inwards mind that for every four-human foot interval there should live no more than than ½” of sagging duct.

Allowable suspension distance and sagging for flexible ductwork

Whatever straps too interruption equipment yous function should not constrict the torso of the ducting. This would undermine the whole point of suspending in the outset home as it would constrict airflow too. Oftentimes the rafters of attics are used to suspend parts of the flexible ducting.

Ridged Inner Surface Affects Airflow

Rigid ductwork is typically rattling efficient when it comes to the airflow throughout the house because of its shine interior surface. Conversely, flexible ducts are non as smoothen every bit they accept coils that permit them to be flexible. These coils increase the internal surface areas as well as create more friction when air flows through them.

Even when perfectly installed, flexible ducting is the less efficient option when it comes to maximum airflow.

The master consequence alongside increased friction is it volition cause your HVAC system to run harder than it needs to push air through the vents. This is likewise why the required fan size is unlike depending on what type of ducting you function.

Air that is exhausted to the exterior of the abode through a flexible duct takes longer to reach the last vent equally a effect of the internal friction. Ultimately, this has the potential to decrease the quality of air inwards your domicile because “one-time” air takes longer to go out, delaying the inflow of “fresh” air.

Less Durable Than Sheet Metal

One of the biggest upsides to utilizing rigid ductwork is the durability and longevity of the canvas metal it’sec made of. Rigid ducts have a lifetime between 20-25 years. However, alongside proper upkeep they tin in all likelihood terminal yous longer.

Unfortunately, flexible ducts are not and so robust, alongside a maximum lifetime of around fifteen years. Oftentimes, flexible ducts are used equally a temporary fix too acknowledged equally so. Very rarely y'all volition see flexible ducts beingness used for the chief torso of a ventilation organisation.

Given that flexible ducts are used inwards tight, cramped spaces, such equally an attic, about exterior factors may play a part inwards the attrition of the duct. One of these factors is rodents, which are drawn to these spaces. Although they may non chew through the entire duct, they volition definitely desire to sink their teeth into the fiberglass insulation.

The maximum lifetime of Flexible duct is around 15 years, holes in ducts can be caused by rodents while rigid ducts lifetime is between 20 to 25 years or more

Sharp objects of whatever sort are a job for flexible ducting besides. Considering it tin can be cutting alongside scissors or a measure knife, it’s non also far of a achieve to mean that it could live split open up peculiarly when stretched out completely.

All of these factors brand flexible ducting unreliable to roughly extent as any of these issues would phone call for a replacement. In the long operate, flexible ducting could essay to be more than costly than installing a rigid duct.

Hard to Clean

The result alongside cleaning flexible ducts is all of the ridges in addition to curves inside the tubing. Unlike stiff ducts that tin can live cleaned amongst a vacuum or physically removed and cleaned past paw, flexible ducts are hard to withdraw or become a vacuum into.

Another job alongside cleaning the flexible ducts is getting them dorsum into home. Even if y'all were to have them down in addition to make clean them out, you lot work the adventure of many of the issues stated previously.

If non properly restored to the master firmness, the flexible duct could sag or be compressed resulting inward reduced airflow too HVAC inefficiencies.

Cannot Be Used for Dryers or Range Hoods

Flexible ducts cannot live used to vent a dryer equally they don’t come across the standards gear up out inwards the International Residential Code (IRC). Section M1502.4.i of the IRC states:

“Exhaust ducts shall take a smooth interior complete and shall be constructed of metal not less than 0.0157 inch (0.3950mm) in thickness (No. 28 approximate).”

There are close to flexible ducts that you lot may detect that come across the touchstone thickness required by the IRC, nonetheless, the foil interior riddled alongside coils and ridges volition definitely non choke equally a “shine interior finish”.

The argue this rule exists is that using a flexible duct to vent a dryer tin can easily lead to lint build-upwards leading to dryer inefficiencies too equally the potential for a burn down on account of the lint build-upward.

Range hoods are the same. You cannot purpose a flexible duct to vent these every bit grease volition make upwards, creating a burn chance, together with the ridges make the arrangement rattling hard to make clean. The rule for this i is constitute inward Section M1503 of the IRC.

While the pros in addition to cons of flexible air ducts are skillful to know, sometimes it is amend when your options are compared comprehensively. If you lot are interested inwards more information, y'all can cheque out Flexible vs Rigid Ductwork: Which Should You Choose?