Flex duct is commonly used in crawl spaces. That said it is vulnerable to punctures, animals and other hazards. Animals have no particular reason the chew the ducts, but sometimes they will anyway. Flex duct is cheaper to install than hard duct, and (at least initially) it is easier to make it not leak.

What is the main problem with flex duct?

Too often, flex ducts are not installed properly, and they end up kinked, bunched up, undersized, or sagging. These issues can cause increased resistance in the duct system, resulting in too little airflow reaching a building’s heating and cooling equipment.

Can flex ducts grow mold?





Mold grows in ductwork when two things are present: moisture and warm temperatures. A warm, humid environment has the ideal conditions for mold to form. A humid climate along with poor ventilation, or anything that traps moisture in your walls and causes condensation, can lead to mold in air ducts.

When would you use a flexible duct?

Flex duct can be used in an attic. In fact, flex duct is one of the most commonly used ducting in attics. This type of ducting material is used so frequently in attics because it is far easier to install than rigid ducts, and it is likely to take up less space in this area of a house.

Can flex duct lay on ground?

With the duct being on the ground plastic or not this will still cause uneeded ware and tare. A solution might have been to use flex duct insted. It is round and can fit in tight spaces better. Even though there is a few small holes in the supply duct it will probably not be enough for the area.

What is the disadvantage of flex duct?

The downside of flex ducting is that it is considered temporary with an acknowledged lifespan of only about 15 years. Another major disadvantage is that they are a little too flexible, so they are often incorrectly installed. And with greater friction than metal ducts, proper sizing is critical.

How do you install a flex duct in a crawl space?





Quote from the video:
Quote from Youtube video: We don't want the heat from the it's that's going through all these ducts here just to go ahead. And go into the crawlspace. So I get this over here all the way. Up against the fitting.

How do you remove mold from flex ducts?

For non-porous surfaces (such as steel ductwork and vent covers), you can use 1 part bleach with 16 parts water. Pour the mixture into a spray bottle for ease of application. Alternatively, you can purchase an EPA-approved mold killing product. Also, purchase an EPA-approved mold inhibitor to apply after the cleaning.

Can flex duct be cleaned of mold?

Depending on the duct material type, different cleaning methods and charges apply. Removing mold from bare sheet metal is much easier. However, if your ducts are made of fiberglass or insulated internally with fiberglass duct liner, they can’t be effectively cleaned and should be replaced. Hire a mold removal company.

Is duct cleaning a waste of money?

Because we believe it’s a waste of money for our customers.



Here is what they concluded: “Duct cleaning has never been shown to actually prevent health problems. Neither do studies conclusively demonstrate that particle (e.g., dust) levels in homes increase because of dirty air ducts.

How long does flex duct last?



10 to 25 years

What is the functional lifespan of a flexible duct system? A search of industry articles, blogs, and chat rooms indicates it lasts from 10 to 25 years. Most flexible duct manufacturers warranty their products for about 10 years.

Is flex duct better than hard duct?

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, making them ideal to build an entire HVAC system.

How long can you run flex duct?



5 feet

An International Association of Plumbing and Mechanical Officials committee has approved a change to the group’s Uniform Mechanical Code, limiting the use of flexible ductwork to 5 feet or shorter runs. Flex duct manufacturers oppose the limitation.

Is Flexible ducting any good?

Flexible ductwork is made of a thin, pliable material. Not only does this make it less durable than metal, but it also means that flexible ducts are more likely to become damaged in the short term. It’s difficult to install the material without damaging it, as rips and tears can happen very easily.

Does Flex duct reduce airflow?

Since flex duct, by definition, is flexible, it often flexes in ways we don’t want it to. The result is poor airflow and ineffective HVAC systems.

Can you use flex duct return air?



Yes, you can use flex ducts for your return air. However, to maximize its usefulness, it needs to conform to technical specifications such as its insulation rating, pressure checks, dust filters, duct sizing and placement, and lastly, the installation requirements.

How do you insulate flexible ductwork?

Quote from the video:
Quote from Youtube video: Take your flexible duct peel back the plastic liner. Then peel back the fiberglass insulation to expose the inner liner. The inner liner goes around the take off all the way around and it smooshes.

How do you secure a flexible duct?

Quote from the video:
Quote from Youtube video: Take the black side of the band your gun to the neck of the duct. And this is going to ratchet tie it and then clip it once it's tightened.

Is flex duct fire rated?

Fire rated flexible duct connector is one manufactured using approved flame-retardant fabric. The fabric can withstand elevated temperatures when dealing with air and fumes.

What is the difference between R6 and R8 flex duct?



R8 ducting uses thicker insulation than R6 ducting. This means that if you were to do air conditioning installation using R8 ducting, you get better insulation than if you are using R6 ducting. When it comes to efficiency of heat insulation R6 ducting is less efficient than R8 ducting.