Marian Pengyan Han discusses key aspects of fabric air dispersion system design and application and demonstrates why fabric ducting has an edge over traditional ducting systems.

Fabric Air Dispersion Systems (FADS) with a host of new technologies and innovations has come a long way in the last 30 years. It has proved to be functionally superior to traditional ductwork, with regard to Indoor Air Quality (IAQ) and workplace productivity and has added a key element to interior design. The challenge in the sector, however, is to combine diverse elements like consistent fire retardant property, lifecycle, controllability of air dispersion, draft-free comfort and energy conservation.

Fire retardant property

When textile material is substituted with steel ducts, the priority is to ensure that the material used demonstrates consistent fire-retardant property. This can be achieved by the process of post treatment. This involves dipping polyester yarn or fabric into a fire-retardant chemical solution, or laminating a fire-retardant chemical layer on the fabric. Another reliable as well as a superior method is the inherent fire-retardant method. This consists of blending fire-retardant additives with polyester chips, melting and extruding it as yarn and weaving it into a fabric. This results in uniform dispersion of the fire-retardant additive, integral to the polyester body.

Good IAQ demands duct cleaning. The major advantage of using fabric in ducts is that they are washable. However, it needs to be noted that post-coated fabrics tend to lose their fire-retardant property through frequent wash cycles, whereas, the inherently fire-retardant material continues to retain its property despite going through several wash cycles.

Fabric permeability

The fabric used in FADS can discharge air either through the orifices and/or by permeation through the fabric’s pores. The choice of fabric and design of orifices play an important role in prevention of surface condensation, achieving the following:

• Design terminal velocities
• Directing cold supply air distribution to occupied levels
• Avoiding cooling high level spaces

Refrigeration equipment in places like departmental stores consumes a huge amount of energy. Using special fabrics with engineered permeation levels has resulted in energy saving and prevents ice formation, and subsequent malfunctioning of equipment.

It needs to be remembered that when due consideration is not given to choice of fabric permeation at the design stage, it could lead to unstable installation with possible wobbling of ductwork at static pressure or velocities varying from duty design.

Innovations in fabric ducting system

Design and application innovations in FADS give users a wider choice. A few of the options are:

• Fabrics with anti-microbial treatment for areas demanding high-level of hygiene
• Anti-static features for electronic equipment
• Apart from generic shapes like circular, semi-circular and quarter circular ones, they also come in shapes like rectangular-shaped fabrics for lower ceiling heights and smooth tapered ones for long ducts

When we take all the key aspects and advantages of Fabric Air Dispersion System into consideration, it is evident that it is suitable for most applications involving ducted air distribution.

The writer is Assistant Manager, Business Development, BESTPRO, Dubai. She can be contacted at: marian@bestprodubai.com