Flexible Duct Manufacturer

Premier Flexible Duct Supplier in China

As a professional Flexible Duct Supplier, Biyang has been in the Flexible Duct of HVAC industry for more than 10 years.  Our Flexible Duct contains various products, such as Aluminum Flexible Duct, Stainless Steel Flexible Duct, Flexible PVC Ducting, Insulated Flexible Duct, Non-Insulated Flexible Duct, Acoustic Ducting, Semi-rigid Aluminum Duct, Light Proof Ducting, High Temperature Flex DuctRectangular Flexible Ducting and so on.  Our Flexible Duct enjoys great sales in Japan, USA, Canada and many other countries all over the world.

Biyang Flexible Duct, also called Flexible Air Duct, is widely used in various HVAC ductworks and dust or fume suction.  With good flexibilities, it is easy to fit into different connectors or rigid ductworks.  It can also be bended or even twisted in the limited space or complicated systems.  In addition, Biyang Flexible Duct is of space saving during the container loading, which saves your shipping cost.

Based on the extent of flexibilities, Biyang Flexible Duct can be divided into full Flexible Duct and Semi Rigid Duct.  The former can work in a proper way even they are twisted, but the late has the less flexibilities.  In addition, you can also judge this from the compressing ratio.  The common full Flexible Duct compression ratio is above 1: 15 or even 1:25.  The common length can be 10m.  However, the Semi Rigid Duct is like 1:3, or even less such as the Stainless Steel Flexible Duct with maximum length 4m.

As a top ranked Flexible Duct Supplier, Biyang uses many different kinds of materials for our Flexible Duct.  The current materials can be divided into Aluminum, PVC, Stainless Steel,  Reinforced Glass Fiber, PET and so on.  Aluminum foil is the most important material in the Flexible Duct.It can be made into the Aluminum Flexible Duct, Semi-rigid Aluminum Duct, and Light Proof Ducting(PVC Combined Duct).

With fire resistant aluminum foil, fire-retardant glue, galvanized or stainless steel inner structure, all these ducts can work in the high temperature environment, normally from -30℃ to +150℃.  These Flexible Ducts can be used as the kitchen ventilation duct, air heating duct, dryer vent duct, dust collection duct and so on.

If you are looking for ducts to be used in the extremely high temperature, Biyang High Temp Flexible Duct will be your right choice.  Biyang High Temp Flexible Duct is made out of reinforced glass fabric combined with aluminum foil.  It is flexible with compression ratio 1:10.  The maximum working temperature can reach +1000℃.

Insulation is always a significant factor in the HVAC Flexible Duct Hose.  Biyang Flexible Duct covers Insulated Flexible Duct as well.  Biyang provides several insulation materials for your selections.  The common yellow fiberglass core is the economic one and is most widely used.  The red Owens insulation is of better elastic features.  The white non-woven fabric insulation is the most expensive but also the most environmentally friendly.

The white non-woven fabric insulation is also the best for Acoustic Duct, which remarkably reduces the vibration and noise level.  Different insulation standards are available in Biyang, such as R4.2, R6 and so on.  You can always find the right insulation based on your country standards and project requirements.  In addition, Biyang also offers optional features such as antimicrobial additives which helps maintain a longer life expectancy for the duct and a healthier air environment.  If you have any new idea to be achieved, Biyang will be your partner to help you.

Biyang, as one of the famous Flexible Duct Manufacturers, has all common sizes for different Flexible Ducts.  The most popular Flexible Duct sizes are 8-inch Flexible Ducts, 24-inch Flexible Duct, 12-inch Insulated Flexible Duct, 4-inch Insulated Flexible Duct and so on.  For special sizes, we can also custom for you.  In addition to the common round Flexible Duct, Biyang also provides Rectangular Flexible Ducting.  This is a good product to work as the temporary connector for galvanized or stainless steel rectangular ducting.

As an experienced Flexible Duct manufacturer, Biyang also provides all kinds of fittings and accessories of Flexible Duct, such as Hose Clamp, Flexible Duct Connector and so on.  This will be a great convenience for you to have a one-stop solution for your HVAC projects.

Biyang always gives you options, including packing method for our Flexible Duct.  If it is for your own project, bulk packing might be a good option.  This saves the packing cost and also shipping cost.  However, if it is for retail, each piece in one white carton with your logo might be a good choice though the packing cost and shipping cost is higher.  For places like Australia, goods with pallets might a good option for easy unloading and saving labor cost.  We can always get the right packing for you.

Anyway, if you have any need or questions for Flexible Duct, please kindly contact Biyang for an inquiry now.  Let’s Biyang help you to complete your project and expand your business.

How We Help Your Business & Projects

  • Full flexible duct product available
  • Custom product development and production based on your requirement
  • One stop solution for flexible duct accessories

Flexible Duct

The Flexible Duct, or flexible ductwork, is one of the most important elements in the HVAC applications, not only in commercial buildings, but also in daily residential housing. The Flexible Duct helps deliver and extract air in the whole system like common air duct. The advantage of the flexible duct is that it can can be folded into a certain angle, and even twisted in the real applications. This makes it possible to have air flow in the way we designed in a limited space. It also facilitates our ventilation system designing and setting up. Whether for a large airport, or a small house, the flexible duct is normally an indispensable part of the whole ventilation and air conditioning system.

Here we will give a complete guide for the Flexible Duct so that you can have a better understanding about the flexible duct and choose the right duct for your own HVAC system project.

Chapter 1: Different Materials of Flexible Duct

There are various of flexible ducts in the HVAC ductwork. If we distinguish them based on materials, there are following common ducts, all of which can be provided by Biyang.

  1. Aluminum Flexible Ducting
  2. Stainless Steel Flexible Duct
  3. PVC Flexible Duct
  4. Semi-rigid Aluminum Duct
  5. High Temperature Duct
  6. Nylon Duct

1.1 Aluminum Flexible Ducting

Aluminum Flexible Ducting, or flexible aluminum duct and aluminum flex duct, is the most common flexible duct in the HVAC applications. It is made of aluminum foil and helix structure steel wires. With steady structure and system, the whole duct can be expandable in an easy way without breaking. With its flexibilities, the standard 10m aluminum flexible ducting can be compressed to fit into a small bag. This significantly reduces the shipping volume and costs.

Flexible Aluminum Duct vary in different diameters, and the common sizes in Biyang Ducting is 2.5” to 24”. There could be different layers of aluminum foils based on the requirements of the applications.  In addition, you can also get the strengthening aluminum foil for tougher tearing and pulling standards.

Aluminum Flexible Ducting

For any Biyang can afford you all.

1.2 Stainless Steel Flexible Duct

Biyang Stainless Steel Flexible Duct is a newly developed corrugated product with SS304, which is a kind of round spiral metal duct.  Stainless Steel 304 contains chromium and nickel which makes the duct more corrosion resistant.  In addition, it is totally non combustible and can be used in much higher temperature than the aluminum flexible ducting.

From the picture outlook, you might take the Stainless Steel Duct as the aluminum semi-rigid duct.  However, when you have it in hand, you will see that it is much stronger in surface, and less flexible.

Stainless Steel Flexible Duct is an excellent choice for the extreme terrible environment.

Stainless Steel Flexible Duct

PVC Flexible Duct / Light Proof Duct

PVC Flexible Duct, or PVC Flexible Duct Hose is a kind of flexible plastic duct hoses.  It is made out of temperature resistant PVC and galvanized steel wires.  For different applications, we can use one layer, double layers, and triple layers of PVC to make a duct.  Of course, for tougher and higher temperature standards, we can use aluminum foil combining into the PVC layer to get the better performance PVC Flexible Air Ventilation Duct.  For such duct, it is extremely suitable to used as the light proof duct in the green house.

When selecting a duct, it is better that you can share the usage with the supplier.  In this way, the professional duct manufacturers like Biyang will recommend you the right duct.

Due to the features of plastic, you will have a variety of color choices for PVC Flex Ducts.  For different applications, you might choose different colors.  If you are interested in this, please directly jump to Duct Applications.  Of course, you can also Contact Biyang for get the guidance for your specific application.

PVC Flexible Duct

1.4 Semi Rigid Aluminum Duct

Semi Rigid Aluminum Duct is different from the common rigid aluminum ducting, mainly due to the flexible features and product structure.  It is also called the Semi Rigid Flexible Aluminum Duct due to the flexibility.

This Semi Rigid Flexible Duct is similar to the Stainless Steel Flexible Duct in the production method, both from metal sheets directly.  It can be bended in a required angle without much force.  As a result, the Semi Rigid Aluminum Duct is widely used in the dryer venting, bathroom and kitchen ventilation and so on.

Semi Rigid Aluminum Duct

1.5 High Temp Flexible Duct

High Temp Flexible Duct, also named High Temperature Flexible Duct, is a kind of ducts used in high temperature environment and applications, such as in the fume extraction, furnace, hood and chimney air applications.

The normal High Temperature Flexible Duct Hose is made of high quality reinforced glass fabric with aluminum foil.  Biyang offers different colors of High Temp Flexible Duct to meet different temperature standards, from +150℃,+250℃ to +400℃.

In addition, silicon coating can be applied to the duct to maintain the steadiness of the fire retardant features.

High Temp Flexible Duct

1.6 Nylon Duct

Nylon Duct is made of nylon fabric and galvanized steel wire.  It is flexible and high temperature resistant with max. temperature around +150℃.  The common lengths for such ducts are 7.5m and 10 meters.

Nylon Duct

Chapter 2: Fire Resistance, Insulation and Custom Features

For all kinds of flexible ducts, many features and functions are required in the different environments.  As a result, you need pay special attention when selecting a right flexible duct.  Here we will share with you some basic knowledges for fire resistance issue, insulation option, and some custom features.

2.1 Fire Resistance

Fire resistance is one of the most common features required in the flexible ducts, especially in the fume extraction, high temp vapor exhaust and so on.  For some industrial air treatments, the whole flexible ductwork should be fire rated, including the using the fire rated duct insulation.

Generally speaking, the fire resistant feature largely depends on the ducting material itself.  Aluminum is more fire resistant than the pvc.  For the extreme fire resistant required applications, you need to choose higher standard fire rated duct material, like glass fiber fabric.  Of course, some coating will increase the performance of fireproof ducting, such as the silicone coating.

Different countries have different standards on the flexible ducting fire rating standards.  For example, Biyang flexible ducts have the SGS fire rating standard AS/NZS1530.3.

If you have specific requirements, you can contact Biyang for details.

Fire Resistance

2.2 Duct Insulation and Insulated Flexible Duct

The duct insulation is very important in the HVAC ductwork system.  Based on insulations, we can divide the flexible ducts into Insulated Flexible Duct and Non Insulated Flexible Duct.

The common materials used for duct insulation are yellow fiberglass, pink Owens glass fiber, and white non-woven fabric.  Different countries have their own preferences on the insulation material.  For an example, pink Owens are popular in US while white non-woven fabric is most common in Australia and New Zealand.  Based on different requirements, the insulation have different standards such as R8 flex duct, R6 flex duct and so on.  The R value is to do with the fiberglass or fabric density and thickness.

The standard sizes for the insulated flex ducts are from 3’’ to 20’’.  However, the most popular sizes for Insulated Flex Duct is 6 inch insulated flexible duct and 4 inch flexible duct in Biyang.

Duct Insulation and Insulated Flexible Duct

2.3 Custom Features

Sometimes, we will require relatively higher performance at a medium cost for the flexible duct.  For an example, we want a cleaner and greener air ventilation system at an affordable cost.  In this way, instead of enhancing the whole system material, we can use the antimicrobial additives to maintain the sanitation of flexible duct, especially for the insulation part.  This is to spend the limited money on the critical part.

Besides, the black treatment and VMPET treatment for the aluminum flexible ducting both help improve the energy saving of the duct.

Custom Features

Anyway, when you have the specific need, you will need to consult with your manufacturer or supplier to get a cost competitive solution.

Chapter 3: Ventilation Duct Production

For flexible ventilation duct production, there are mainly two types based on the structure of the flexible ducts.   One is flexible duct making, and the other is like the semi rigid ducting making.

3.1 Flexible Duct Production

One is based on the combinations between soft material(aluminum foil, pvc, nylon, glass fiber fabric and so on) and the steel wire with glues and structure.

For materials, glue is an important part in the flexible duct.  Firstly, we need to make sure the glue is also fire resistant.  In addition, we want to make sure the glue is “green” style.  That is to say, it will not release poisonous chemical elements when using in the ventilation ductwork even in high temperature.  Otherwise, it will be a big threat to the health.

For the flexible duct productions, the duct machines have got big improvements over these years.  For the old style machine, the worker do the cutting when the duct reach the required length.  However, currently, the machine will automatically cut the duct.  In addition, the speed of ducting making also increases.  This significantly saves the labor costs and reduces the product cost.

Here is a video for checking the flexible duct production, combining the aluminum foil and the galvanized steel with fire resistant glue.

3.2 Semi Rigid Ducting Production

The 2nd one is mainly the semi rigid duct, such as the semi rigid aluminum duct and flexible stainless steel duct.  This type of ductings is made out of metal sheet directly.  The machine is used to add curve and texture of the metal sheet surface and interlock it with the whole system structure.  The structure and surface corrugated design make the whole duct flexible.  Of course, such duct will not be as flexible as the 1st one due to the structure.  The advantage of this duct is that it is self-supporting.  Once it is bent, it is steadier to keep this shape if there is no outside force.

Here is a video to check the semi rigid duct production.

Chapter 4: Flexible Duct Accessories

For flexible duct setting up in different applications, the ducting accessories are the indispensable part.  Here are common accessories.

4.1 Hose Clamp

For most flexible ducts, they are not self supporting.  When we connect them to other parts, we need to fix them with the hose clamp.  For the hose clamps, different countries have different styles.  If you want to buy the bulk for the projects, specifications and requirements must be studied before buying.

Hose Clamp

4.2 Duct Insulation Sleeve and Duct Jacket

For some non insulated flexible duct, it is quite easy to add the insulation layer with the help of duct insulation sleeve or duct jacket.  The jacket material can be aluminum or PVC outside to be a barrier for the vapor.  With Biyang Duct Jacket Sleeve design, it is easy for you to put the into the sleeve.  In this way, your ducting system can be more energy saving.

Duct Insulation Sleeve and Duct Jacket

4.3 Foil Duct Tape

Right foil duct tapes or fire resistant duct tape should be applied in the HVAC ductwork.  For some some flexible ducts, we should seal the steel wire into the outside fabric in the cutting place.  This will help avoid the finger cutting when duct setting up.

In addition, for high temp applications, you should always use the fire resistant tape for safety reasons.

Foil Duct Tape

4.4 Duct Connector

The duct connector connects two parts, whether from big ducts to small ducts, or round duct to square duct.

Duct connectors can be made out of metal sheet based on rigid ducting connector.  It can also made out of the Flexible Duct Connector materials, such as nylon, polyester, and glass fiber material.  If we are using in the high temperature environments, the fire rated flexible duct connector like glass fiber duct connector is a good choice.

Duct Connector

Due to so many applications, there might be some details not covered in this flexible duct guide.   If you want to learn more about the flexible duct and accessories, please feel free to Contact Biyang.