The Optimization Design and Local Resistance Loss of Fabric Air Duct
With the in-depth study of the air supply principle of the fabric air duct system, the design method of the fabric air duct becomes maturer and maturer, including the study and calculation of the on-way resistance inside the fabric air duct.
There are also pressure losses due to the frictional resistance and local resistance along the length direction of the fabric air duct system. Because the pressure loss is proportional to... moreThe Optimization Design and Local Resistance Loss of Fabric Air Duct
With the in-depth study of the air supply principle of the fabric air duct system, the design method of the fabric air duct becomes maturer and maturer, including the study and calculation of the on-way resistance inside the fabric air duct.
There are also pressure losses due to the frictional resistance and local resistance along the length direction of the fabric air duct system. Because the pressure loss is proportional to the wind speed, when the wind speed along the length direction becomes smaller and smaller, the resistance loss also decreases continuously. At the same time, there are also local resistance losses at the standard parts of the air duct and at the air outlets.
The main part is the straight duct in the fabric air duct system, and there are a few tee-junctions, elbows, and reducings in the system. Generally, the on-way resistance loss is the main resistance loss form. The frictional on-way resistance of the airflow in the duct with the unchanged air cross-section shape is calculated as follows:
The frictional resistance coefficient; the average velocity of the air in the duct, m/s; the air density, kg/m3; the duct length, m; the diameter (inside diameter) of the round air duct, m. The frictional resistance coefficient is a variable value, which is related to the flow condition of air in the air duct and the roughness of the duct wall. The frictional resistance coefficient obtained is no more than 0.024 (about 0.019 for the iron air duct) according to the comprehensive study on the fiber material and the fabric air duct system. The average wind speed in the air duct is 1/2 of the speed at the inlet of the air duct because there are air supply holes in the extension direction of the fabric air duct. It can be seen that the on-way resistance loss of fiber air ducts is much smaller than that of traditional iron air ducts.
To reduce the local resistance loss of the fabric air duct system, we usually carry out certain optimization designs:
1. Multiple factors should be taken into consideration when choosing the duct diameter, and try to reduce the wind speed in the duct as much as possible.
2. Optimize the design of special-shaped parts to avoid too rapid a change of flow direction and too fast a change of section.
It can be seen that the on-way resistance loss of the fabric air duct system, especially the straight duct system, is very small and generally, it will not exceed the static pressure regain value, so the resistance loss can be basically ignored in rough calculation!
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Asia-P... moreContact Us
Thank You For Your Interest In Durkee's HVAC Air Duct Solution.
Do you have questions about any of our fabric air duct systems? Need a quote or consultation for your project? Let us know, and we'll follow up with you right away.
Your Name *
Your Email *
Your Phone *
Type Service *
Your Message *
SEND Message
Add:NO.8, West Renmin Rd., Gedian Development Zone, Hubei ,China
Email:durkee@durkeesox.com
Tel:+86-27-59237477
Web: Durkeeglobal.com
Sales Center
Asia-Pacific Regional Offices
Asia-Pacific Regional Offices
Durkee Asia Pacific PTE Ltd
The Comparison Between Fabric Air Duct and Galvanized Iron Air Duct (Part II)
(4) The influence on floor height
An insulation layer needs to be wrapped outside the galvanized iron air duct on site, and the insulation layer often requires replacement when carrying out maintenance, so in addition to the height of the duct itself, a certain space for installation and maintenance should be reserved.
The fabric air duct itself has the thermal insulation effect, so it can be installed close to the ... moreThe Comparison Between Fabric Air Duct and Galvanized Iron Air Duct (Part II)
(4) The influence on floor height
An insulation layer needs to be wrapped outside the galvanized iron air duct on site, and the insulation layer often requires replacement when carrying out maintenance, so in addition to the height of the duct itself, a certain space for installation and maintenance should be reserved.
The fabric air duct itself has the thermal insulation effect, so it can be installed close to the roof without reserving the space for installation. The measured results show that the use of fabric air duct can save about 5 -10cm in height compared with the use of galvanized iron air duct.
(5) The service life of galvanized iron duct
It is easy for galvanized iron sheet to rust in a humid environment, and the glass fiber, another kind of insulation material commonly used in galvanized iron air duct, will become brittle after moisture absorption, therefore, the service life of galvanized iron duct is about 5 to 10 years. While the textile air duct has a service life of up to 20 years. From this point of view, the service life of fabric air duct is much longer than that of galvanized iron air duct.
(6) The noise elimination performance of galvanized iron duct
Galvanized iron air duct is a kind of rigid duct without noise elimination effect, and it will even send the noise produced by the equipment to the workplace, so other noise elimination accessories such as sound proof housings and hend mufflers are needed. In addition, when suddenly encountering cold or hot wind, the galvanized iron air duct will produce stress deformation due to thermal expansion and contraction, so as to bring the annoying croaking. On the contrary, the fabric air duct is soft in texture and has good noise elimination performance. It is a very good tubular muffler, so there is no need to conduct noise elimination treatment, which can reduce a lot of troubles.
(7) Hygiene and health of galvanized iron duct
Galvanized iron air duct is easy to rust and produce the cold bridge phenomenon, so the dew formation is prone to occur. Therefore, bacteria such as legionella are easy to breed in galvanized iron air duct, resulting in secondary pollution to the air supply. In addition, the glass fiber, an insulation material commonly used in galvanized iron air duct will do harm to human health to some extent. Instead, the fabric air duct is not easy to produce condensation water, which can avoid the generation and spread of bacteria. Therefore, from the perspective of hygiene and health, fabric air duct is far better than galvanized iron air duct.
As is analyzed above, in practical application conditions, the performance and use of fabric air duct are much better than those of galvanized iron air duct in all aspects. Therefore, the combination of fabric air ducts can break through the limitations and inconvenience of traditional air ducts in the application of central air-conditioning air duct, which is worth being applied and promoted in various industries and fields. #iron#duct https://www.durkduct.com/comparison-fabric-air-duct-and-galvanized-iron-air-duct-ii.html
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