Features of high temperature duct hose and its installation

Insulation performance

The wall of the high temperature resistant air duct is made of centrifugal fiberglass panels. The thermal conductivity is small (0.029W/m.K at an average temp of 24℃ and 0.04W/m/K at 70℃). In particular, the exterior composite aluminum foil cloth has high heat reflection capabilities. And its strength and toughness are much higher than aluminum foil paper. Besides, it is not easy to be damaged. The pipe wall is the insulation layer. The pipes adopt tenon joints, T-shaped inner frame butt joints and iron sheet plug joints (or outer flange connections). Therefore, all parts of the entire high-temp-resistant duct hose are evenly insulated. And there is no cold bridge phenomenon. So it has good thermal insulation performance. However, galvanized iron air ducts and inorganic fiberglass duct hose have no thermal insulation property. In addition, you must add an additional insulation layer and protective layer.

Air leakage volume

You should calculate the air leakage volume of the air duct as a percentage of the system air volume based on the length of the duct hose and its air tightness. The air leakage rate of high temp duct hose should be 10% (for general air supply and exhaust systems).

The air duct is connected by slotting, tenoning and gluing. While the joints are sealed with aluminum foil tape. The air leakage of unreinforced high temperature ducting hose is 0. But it is not greater than 1% of the reinforced duct hose. While the system air leakage rate is not greater than 2%. When the static pressure inside the pipe is 500Pa, the air leakage per unit area of the duct is less than 1.8m3/h.m2.

Fire performance

The high temp duct hose uses non-combustible fiberglass cotton board as the base material. And it uses self-made flame retardant adhesive to composite aluminum foil cloth and glass fiber cloth on both sides of the base material. Therefore, the finished air duct is a non-combustible material. It also complies with GB8624-1997 “Classification Method for Combustion Performance of Building Materials”. What’s more, it is Class A qualified with good fire resistance. Although galvanized iron duct hose and inorganic fiberglass ducting are non-combustible materials, whether the insulation materials will burn depends on the material. Originally, polystyrene boards were used as interlayers. Because there will be toxic gases under the action of external fire sources, they will be gradually eliminated. Nowadays, non-combustible insulation materials such as centrifugal glass wool usually serves as interlayers. Due to strength and other issues, product quality is not yet very stable.

Moisture-proof performance

There are no perishable materials and components in the materials used in high temp duct hose. The outer surface of high temp duct hose is made of moisture-proof aluminum foil cloth. Its moisture permeability is 0 and it has extremely strong corrosion resistance. The water absorption rate of the fiberglass board is not greater than 2%. If the pipeline is in a humid environment for a long time, its various properties such as noise reduction and insulation will not change. Because it is a porous material, it is necessary to prevent the inside of the pipeline, pipe ends and cuts from being soaked by water for a long time.

Galvanized iron sheet high temp duct hose are susceptible to moisture, corrosion and rust. It is even more serious when transporting AC air with high moisture content. Especially during the production of high temp duct hose, the galvanized layer is damaged at the bite of the iron sheet. At the same time, it is difficult to repair and anti-corrosion treatment. And condensation will corrode the pipeline where the cold bridge occurs. Thus it will affect its overall life. Inorganic FRP high temp duct hose have poor moisture-proof stability due to the restriction of raw material ratio.

Noise reduction performance

The wall of the high temperature ducting hose is a porous sound-absorbing material. It has a good sound-absorbing effect on medium and high-frequency sound waves. Data shows that when the medium frequency is 1000-2000HZ and the pipe diameter is 500x320mm, its sound attenuation capacity can be 18-21dB/m. Thus it is a good tube muffler which can eliminate the primary noise from AC equipment and the secondary noise generated by valve bodies, pipe fittings, etc. As the pipeline extends, the effect becomes more obvious. So it can eliminate the need for a dedicated muffler. However, galvanized iron high temp duct hose and inorganic fiberglass high temp duct hose have no muffler performance and must be equipped with a muffler.

Strength

The wall of the high temp ducting hose is made of lightweight fiberglass board. Then it is easy to transport and construct. Besides, it can bear the pressure of general ventilation and air condition. When the wind pressure is 500Pa, the deformation of the pipe wall is not more than 1%. While the glass fiber duct pipe with a wall thickness of 25mm can withstand 800Pa static pressure. But it may withstand greater pressure or the side length of the high temp ducting hose may more than 630mm. Then you can reinforce it based on the wind pressure. Then it can withstand wind pressure up to 1500Pa.

Weight

The bulk density of the high silicone duct hose is 64kg/m3. And the weight per unit area is 2.8kg/m2 (thickness=25mm, including the weight of the hanging bracket 1.5kg). It is the lightest among all types of high temperature ducting hose materials. The bulk density of galvanized iron sheet duct is 7870kg/m3. While it is 2100kg/m3 of inorganic fiberglass high temp resistant duct hose.

Frictional resistance

The inner wall of the high temperature ducting hose is made of glass fiber cloth. And the surface roughness is 0.2mm, which is slightly larger than the measured value of the iron sheet ducting hose. When the wind speed in the high temp ducting hose is less than 15m/s, its resistance along the way is similar to that of the iron sheet. The ratio does not exceed 7% (including the resistance increased by reinforced struts in high temp duct hose). While the resistance along the way in general ventilation and AC ducts only accounts for about 10% of the local resistance. (Super high temp duct hose and galvanized iron sheets are resistant to high temp).

The local resistance of telescopic air ducts is basically the same). So the increased ventilation resistance of fiberglass high temp duct hose is less than 1% compared with iron high temp duct hose. Besides, it has no obvious impact on the entire high-temp air duct system. It can basically be neglect. The friction resistance of inorganic FRP high temp duct hose is greater than that of iron sheet high temp duct hose. And it is close to that of composite fiberglass plate high temp duct hose.

The fiberglass shielding ability of high temp resistant air duct

The inner wall of the composite glass fiber board high temperature ducting hose is made of composite glass fiber cloth. Thus it has the ability to shield fibers from flying. Under the condition of an internal wind speed of 15m/s, the fibers on the inner wall of the high temperature ducting hose will not fall off. And it fully complies with national health standards and ensuring indoor air quality and environment.

Service life

Composite fiberglass high temp ducting hose is based on glass fiber. It is light in weight, corrosion resistant and anti-aging. Besides, it is easy to disassemble, repair and change pipelines. What’s more, its lifespan can be as long as 10-30 years. Some overseas models have been used for 30 years. There are also engineering examples in China that have been used for more than ten years. Galvanized iron high temp duct hose have poor moisture resistance. Then the galvanized layer will be damaged during process. Then it will be more likely to cause corrosion and rust. While this reduces the overall life of high temp duct hose. In general, the lifespan of high temp flexible duct hose is 5-10 years. Inorganic fiberglass high temp duct hose have poor moisture-proof stability. Although it has high strength, it is fragile and has a service life of 5-10 years.

Construction and installation

The pipeline is heavy, and the production and installation cycle is long and slow. It is a labor-intensive to change the size and direction of the pipeline. Besides, it will cost much time. The insulation layer is installed on site after the high temp ducting hose is installed. The process is cumbersome. When you install the flange into the high temperature ducting hose, it should be insulation. Because if the thickness is not easy to ensure or there is no insulation, it will cause a cold bridge phenomenon. The necessary space for the installation and operation of the insulation layer should be left around the high temp ducting hose. Otherwise, the uniformity of the insulation layer coverage will be difficult to ensure due to insufficient installation clearance. And the appearance will be unsightly. Installing a muffler requires more space and increases installation difficulty and workload.

Inorganic FRP high temp air duct

Pipes are bulky and difficult to transport. They have high strength, but are relatively fragile and are prone to cracking and damage due to collisions. The production and installation cycle is long and slow. And changes in pipe size and direction are labor-intensive and time-consuming, resulting in huge losses. Installing a muffler requires more space and increases installation difficulty and workload. If a mezzanine high temperature ducting hose with insulation is used, it will increase the load-bearing capacity of the building because of its heavier weight.

Composite fiberglass board high temp duct hose

The pipeline is light in weight and it is fast to install. Because the pipeline and insulation layer are integrated into one. Thus the installation process can be completed into one. Then it is easy to make installation changes according to site conditions or designs during the process without affecting other work procedures. Compared with other materials , it can save the operating space of the insulation layer and save 150-200mm of ceiling clearance. In other words, compared with other high temp duct hose, it can increase the height of the ceiling by 150-200mm.

It has a beautiful appearance and is also suitable for surface installation. Colorful paints can also be used for decoration, so as to achieve harmony and unity with the surrounding environment. Because of its light weight and short installation period, it is in line with the development trend of modern architecture pursuing lightweight materials. And it is more suitable for the field of high-rise buildings. But because it is a non-rigid material, it must be handled with care, processed and stored as required. Technical workers are required to operate the construction in a civilized manner to avoid human damage.

Typical applications of high temp duct hose pipe

Above are the features of high temp flexible duct hose and the installation. In fact, high temp duct hose is almost used in any civil and industrial fields. In the welding workshop, you need it to exhaust the high temp welding gas. While in the steel factory, you need it to discharge the extremely high temp air. In the basement, it plays an important roll in air conditioning. With it, you can exchange the air in the basement. What’s more, the farmer use it to deliver hot and cold air to the cow house. Then the cows can be alive in summer and winter.

Orientflex is the duct hose manufacturer that you can not miss

Since setting up in 2010, we focus on the R&D and exportation of flexible hoses and couplings. As one of the most important series, our duct hose is popular in the world. Because it performs vert well in any uses while costing less. Therefore, it is the cost-effective choice for the users. Besides the high temp duct, we can also provide you PU steel wire duct hose and PVC helix duct hose. Both of them have excellent wear resistance. At the same time, they are your good assistants for material handling. If you have the need to deliver high temp air, don’t hesitate to contact us and get the best quotation.