Fabric duct sizing with fittings


Is it possible to design fabric fittings, for change of direction in the network (elbows, connexions…) ?

This is where fabric duct comes in handy! Indeed, when we need to diffuse on long lengh we sometimes need to bring the air from the blowing unit to the desired area.
 
This air distribution may require fittings to adapt to the building’s specificties as pipework, cable trays  or walkway. In these cases we may include fabric pieces such as elbows, transitions or connections.
 
These pieces can severely increase the final cost when dealing with sheet metal networks. Besides, installation time increases with access complexity.
 
On the contrary, designing fabric pieces eases handling and installation.

How to design a complex aeraulic network with fabric ducts ?

Designing and sizing fabric ducts or difusers requires to take into account the network’s geometry and its frontal speed
We would advise to follow ATC’s recommendations regarding velocity to avoid risks such as :
  • Duct’s flapping or waving
  • Noise levels
  • Duct deterioration
For instance, immoderate frontal speed associated with a change of direction (fittings) creates over-pressure and depressions zones.

These over-pressure and depressions phenomenon leads to fabric ducts instalbility creating distortion, flapping or waving which may damage the fabric.


You expect a high quality aeraulic network? Then, respect the speed limit recommendations.

When designing an aeraulic network with fittings taking into account speed limits is essential. Respecting recommended speed limits will allow you to obtain a quality network while avoiding lifespan issues.  
You can see below what happens with your fabric duct when you do not respect the recommended speed limit:

To put it in a nutshell, a high air speed’s impact in transition or connexion fittings may create :
  • Distortions and non-complying aesthetic result
  • Quick deterioration
  • Early duct weakening
  • Bad aeraulic performance
 
It is then crucial to be sure network’s geometry is fully adapted to the frontal speed in order to avoid these incidents on your fabric ducts. By the way, don’t forget to read our article on tailor-made solutions by clicking right HERE.
 
Please note that aeraulic networks must be conceived by an air specialist who will be able to properly assist you but most importantly to avoid any issues in the future.
 
 
Feel free to contact our technical team to the following address :  technique@aerotextile.com