Flexible duct is easy to install and has a long lifespan, it is a common choice for bathroom fan ducting. A rigid duct will move air more efficiently and can be used over longer distances, but it is costly and hard to install. Insulated ducting (flexible or rigid) is always better than uninsulated.

Is rigid ducting better than flexible ducting?

Rigid ducts are durable and provide excellent lifetime value for money. Lower airflow resistance leads to greater efficiency and capacity than flexible ductwork. Weather resistant and suitable for external mounting.

Can you use flex duct for exhaust?

No. Avoid flexible duct for your range hood, regardless of the CFM. Flexible duct is a poor investment because it is: Not durable/sturdy.

What kind of pipe do you use for a bathroom fan?

PVC Schedule 40 Foam core pipe is the ideal pipe for bathroom fan venting. This type of piping is non-toxic, easy to install, and is code compliant. The PVC pipe fittings can be safely cemented and sealed, preventing any water that might collect in the pipe from leaking and causing water damage.

What is the best way to vent a bathroom fan?

The fan exhaust must vent directly to the exterior of the home. Do not put the vent termination in a roof overhang or soffit. Don’t put it on a wall near or under a roof overhang. The moist air that’s belched out by the fan can be sucked right up into the open soffit vents and be drawn into your attic.

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 long can a bathroom vent duct be?

Generally a 4 inch flex duct can carry a fan exhaust for up to 25 ft. Most codes require that.

Can you use flex duct for bathroom vent?

Can flexible duct and air connect to bathroom exhaust fans? Yes, that’s correct. We recommend that you use insulated flex duct in long vent run applications to help keep the humidity in the duct and to help prevent the pooling of water which can damage the core.

Should bathroom exhaust duct be insulated?

Regardless of where or how you’re installing your bathroom fan, the accompanying exhaust fan should always be insulated. If you don’t want to deal with condensation, mold, and water damage, insulation is best to avoid it.

Can you use dryer duct for bathroom vent?

Your clothing dryer removes moisture from your laundry and exhausts the moisture vapor out through a duct in order to prevent moisture problems in your laundry room, much the same as your bathroom exhaust fan does in the bathroom.

Is it better to vent bathroom fan through roof or soffit?

Whether it’s new construction or a remodel, a bathroom vent should always vent through the roof instead of an eave, overhang, or soffit. The point of a bathroom exhaust vent, or any vent really, is to remove hot, moist air from the house.

Should you vent the bathroom exhaust fan?

Bathroom fans should always be vented to the outside rather than through the ceiling and into your attic. Venting your bathroom fan anywhere other than outside runs the risk of mold forming. Most building codes will require you to vent your bathroom fan to the outside of your house.

Is it OK to vent a bathroom fan through the soffit?

A bathroom fan can be vented through soffit so that the warm air from the bathroom comes out through it and goes outside. However, It is important to keep in mind it can not be vented into the soffit, as this will lead moisture back into the attic.

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.

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.

Why is there no flex duct?


The flex duct commonly used in Southern California relies on a heavy-duty stainless steel spring for its core. Stainless steel, it turns out, is one of many simple commodities that regularly runs out this year. If duct manufacturers can’t get ahold of stainless steel, they can’t make flex duct.

How often should flex duct be supported?

every once 4 feet

Supports should be installed at least every once 4 feet. The maximum allowable sag in flexible duct is one-half inch per foot. (Source: Calcs Plus.) Place supports at each connection between flex duct and rigid metal duct.

How do you connect a flex duct to a rigid duct?

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.

Does Flex duct sweat?

Flex ducts themselves do not sweat, however if the connection points are not sealed correctly and duct leakage is occurring then you can get sweating at those points. The good news is with a flex duct system we can either hand seal the connection points or perform an Aeroseal to stop the water.

How do I stop my flex duct from sweating?

Try to reduce the humidity level in the air near the air ducts. You can go for a dehumidifier if that helps to reduce the condensation. Unblock any ducts that are restricting airflow and have them cleaned regularly. Regularly clean your air filters and change them once every three months.

How do I stop my ducts from sweating?

What can I do about ductwork sweating?

  1. Reduce the humidity level around your air ducts. Keep ducts spaced apart so air can flow between them. …
  2. Unblock any ducts that are restricting air flow and have them cleaned regularly. …
  3. Keep your air filters clean and change them regularly. …
  4. Repair leaking ducts.