Corrugated air ducts for ventilation: corrugated hoses and corrugated pipes

Corrugated ventilation pipe is very widely used in modern construction. Ease of installation, durability and low cost are attractive. But not in all cases the use of corrugated pipes for ventilation is justified.

Types and application of corrugated pipes for ventilation

Corrugated ventilation pipes have been produced for a little over 20 years. Most often, corrugated pipes are used for ventilation systems of private houses, industrial workshops, warehouses and elevators, mines.

Corrugated pipes for ventilation can be insulated or non-insulated. In addition, corrugated hoses for ventilation are divided according to the type of material:

• plastic (polyvinyl chloride);
• aluminum;
• steel;
• aluminum foil on the frame;
• polyester metallized tape on the frame.

The diameter of the ventilation corrugations is from 100 mm to 500 mm. They select it depending on the power of the equipment and the length of the ventilation ducts. Flexible corrugated pipes are more often used for ventilation of complex configuration, with an abundance of transitions, elevation differences and turns. Moreover, they try to make straight sections from smooth air ducts, connecting them with sections of corrugated hoses for ventilation.

The elasticity of the corrugated pipe for ventilation allows you to use less building materials, create air ducts without sharp corners, which allows you to maintain the pressure and speed of air movement. In order not to violate the integrity of the load-bearing walls and beams, a flexible corrugation for ventilation is simply pulled around them. This installation is less expensive and takes less time.

Flexible elements are also convenient when connecting sections of ventilation ducts at different levels. This is the optimal solution in small, tight spaces where rigid adapters will not fit.

Corrugated ventilation hoses have excellent aerodynamic properties. The pressure of the air flow passing through them decreases only slightly. Thus, the ventilation system works with the greatest efficiency, using energy rationally. The round section of the corrugated ventilation sleeve allows the use of lower power fans. Directly in the ventilation ducts, devices for the redistribution of air flows, sensors and measuring instruments can be placed.

Passing through the ventilation corrugation with a diameter of 400 mm, the air emits less hum than when passing through the ventilation from the corrugation 200. Therefore, the sections of the corrugated ventilation hoses can be considered noise-suppressing.

Aluminum and steel corrugated pipes

Steel and aluminum corrugated pipes for ventilation are classified as semi-rigid materials. They are used in cases where it is necessary to assemble a system inexpensively but with high quality. From the corrugated pipe, sufficiently strong and lightweight ventilation structures are obtained.

Steel and aluminum corrugated ventilation ducts are similar in their properties and meet all technical standards:

• not flammable;
• easy to assemble;
• easily replaced and repaired;
• corrugated hoses provide the ability to inspect ventilation.

Compared to other types of air ducts, corrugated aluminum have a number of advantages:

• lungs;
• ventilation corrugated hoses do not accumulate static electricity;
• does not need to be grounded;
• aluminum withstand temperature limits -35 ... + 270 degrees Celsius;
• corrugated steel ventilation pipes are more heat-resistant and work up to +900 degrees Celsius;
• create sealed structures;
• you do not need to stretch the air duct;
• are not damaged by prolonged exposure to ultraviolet radiation;
• corrugated hoses for ventilation are not subject to corrosion;
• bend to a radius of -0.76.

And one more advantage of steel and aluminum corrugated pipes for ventilation is a neat and pleasant appearance. Such corrugated ventilation ducts do not need to be covered with boxes in kitchens or in utility rooms.

Corrugated aluminum hoses for ventilation without loss of properties have been used for decades. Their installation is very simple: individual pieces are connected to each other using metal tape. And the ability to stretch the original length by 3.5 - 4 times allows you not to purchase fittings.

However, aluminum corrugated ventilation pipes cannot be called a universal material.

In some cases, it is impossible to use corrugated aluminum air ducts for ventilation:

• Since aluminum melts at high temperatures, it is forbidden to install a corrugation of this material as a chimney for fireplaces, stoves and boilers with coal and wood. It is not advisable to install it as an air duct for a gas water heater, where the corrugation gradually burns out and there is a danger of poisoning people;
• Aluminum perfectly conducts temperature, therefore, in the cold season it is a cold bridge. The surface of the aluminum corrugated ventilation sleeve is covered with water droplets, increasing the humidity in the room. To prevent this negative effect, heat-insulated ventilation corrugations are used.

For the convenience of installing aluminum corrugated pipes, various accessories are produced:

• adapters from flexible to rigid pipes;
• adapters between flexible pipes;
• protectors against the penetration of debris and dust into the pipes.

When assembling a ventilation system from aluminum corrugated pipes, general rules are followed. Pieces of ventilation corrugation 400 are joined by couplings or socket joints. Couplings for thin steel pipes of suitable size can be used.

Steel couplings are used as follows:

• the end of the pipe is pulled over the end of the coupling;
• they put on 2 clamps (screw);
• the end of the abutting pipe is pulled over the other end of the coupling;
• the clamp screws are tightened and the joint is firmly pressed.

Since aluminum is very flexible, a properly made joint will be sufficiently tight. It is easy to join two pipes with different diameters by inserting a thinner one into a thick one by 0.5 m, and tightening the structure with a clamp on top.

The use of corrugated ventilation hoses made of aluminum allows you to reduce construction costs and carry out installation in a shorter time.

There are 100 mm, 200 and 400 mm aluminum ventilation belts on sale. Minimum diameter 80 mm, maximum 315 mm.

The aluminum ventilation corrugation is sold in pieces, the price depends on the diameter and length.

Production of aluminum corrugated pipes

A ventilation aluminum corrugated pipe is produced from aluminum foil supplied in rolls. The finished product has a circular cross-section and a wall thickness of 0.06 - 0.12 mm.

The manufacturing process consists of several steps. The foil from the roll (strip) is fed to the rolling machine. Here, locks are pressed along the edges of the strip, and ribs in the middle of the sheet. The ribs give flexibility to the future pipe, the ability to compress or stretch. The strip is wound on a profile with a diameter corresponding to the future pipe. The longitudinal edges of the strips are held together by triple locks through the rollers, which makes the pipe very strong. This is the structure of an elastic pipeline.

Plastic corrugated pipe

Ventilation plastic corrugations are made of polyvinyl chloride and are used to remove dust, gases, air, sawdust. Corrugated air ducts are widely used for ventilation of chemical and furniture industries. The pipe can withstand temperatures from -20 to +65 degrees Celsius.

The material from which the plastic corrugation for ventilation is made has the following qualities:

• elasticity;
• strength;
• light weight;
• chemical neutrality;
• weak flammability;
• resistance to moisture.

Resistance to aggressive environments makes polypropylene pipes ideal for ventilation of chemical plants, laboratories where vapors of organic or inorganic acids are released into the air.

Plastic PVC corrugations for ventilation consist of a steel spiral, on top of which a layer of soft and flexible PVC is applied. Wall thickness - 1 millimeter. The thickness of the wire base is from 2 to 5 mm.

Corrugated ventilation pipe made of PVC is produced with diameters from 15 to 30 cm, in coils of 10 - 50 m. Ventilation corrugation 200 mm can be purchased both plastic and aluminum.

Due to the rigid steel frame, the pipeline is not pinched.

A significant disadvantage of ventilation plastic corrugated pipes is the accumulation of static electricity.

Dust particles adhering to the inner surface of the channels gradually reduce the clearance and deteriorate the aerodynamic properties of the pipe.

Corrugated polyester film and aluminum foil

Flexible air ducts made of polyester film or aluminum foil are an improved analog of plastic corrugated pipes. The wire frame with a pitch of 38 to 45 mm is wrapped in polyester film with aluminum spraying or foil on a layer of polyester tape. For strength, up to 6 layers are wound, therefore ventilation from such corrugated hoses will withstand pressures up to 2400 Pa. Corrugated polyester film pipes are suitable for systems operating in the temperature range -30 ... + 90 degrees Celsius. Foil corrugated hoses for ventilation will withstand up to +130 degrees.

Corrugated hoses for ventilation made of polyester tape and laminated foil are sold in pieces of 10 m. A variety of diameters allows you to choose a ventilation corrugation from 100 mm to 500 mm, including a corrugation for ventilation 400 mm.

Heat-insulated corrugations for ventilation

A thin corrugated ventilation sleeve cools down in the cold season, moisture from the warm indoor air condenses on its walls. Therefore, pipes must be insulated.

It is quite difficult to carefully insulate the corrugated pipe on your own.

Sometimes for this, additional boxes are constructed, filled with insulation. A cumbersome and not always appropriate design is created.

Ready insulated corrugations for ventilation immediately solve the problem of condensation. Insulated corrugation is a multi-layer structure. The inner layer is a flexible air duct made of polyester tape coated with aluminum. Next comes mineral wool wrapped in a protective layer of metallized film. The thickness of the insulating layer is 2.5 cm. The frame of the ventilation corrugation under the insulation layer is made of high-carbon steel wire. To reduce flammability, an aqueous acrylic compound with flame arresters is used.

Purpose of the insulated ventilation corrugation:

• reduction of heat loss;
• thermal insulation of ventilation systems;
• air ducts for air conditioning systems;
• prevention of condensation in the ventilation ducts.

Ventilation corrugations with a layer of insulation are used in air exchange systems with pressures up to 2400 Pa, as peripheral lines for central air conditioners. And as exhaust pipes for ventilation systems of residential and industrial buildings.

There are insulated ventilation corrugations 200, 100, 300 and 400 mm on sale.

Insulated corrugation is sold in 10 m pieces in cardboard boxes.Read more about the installation of insulated corrugated pipes in our video.

Pros and cons of using corrugated pipes for ventilation

The use of corrugated hoses for ventilation has a number of advantages over other materials:

• flexible and easy to bend;
• due to elasticity, it is possible to create the most complex designs of ventilation systems;
• strong enough;
• absorb noise;
• docking sleeves, adapters and corners are not required;
• easy to assemble;
• when folded they take up little space, facilitating transportation;
• suitable for both indoor and outdoor use.

Ventilation corrugations can be combined with square or rectangular ducts. To connect them, adapters from round to square (rectangular) cross-section are suitable.

The flexibility of the pipe makes it possible to assemble ventilation ducts of almost any shape. One-piece elastic tube bends easily by hand to any angle. Structures that are difficult to assemble from rigid pipes are easily assembled from corrugated pipes.

Disadvantages of ventilation corrugated pipes

• Corrugated ventilation pipes are less durable than rigid ventilation ducts. Therefore, they are mounted in such a way that there is easy access for replacement;
• The throughput of ventilation corrugated hoses is lower than that of smooth pipes. This is due to the turbulence of air that forms when passing between the grooves of the corrugation.