Fabric ventilators are universal tool for air distribution. The air from the fabric duct is distributed through the fabrics surface and nozzles or blowing gaps. The combinations of sizes and hole arrangement along with different initial speeds are the wide range of possible configurations of the ventilation system. The range of available options spreads from the distribution of air with low speed up to directed flow for long distances.
Air stream range
Air stream range of particular solutions, measured at the speed of air supply 0,2 m/s and isothermal blowing is presented in the table:
|Average air stream range at the speed 0,2 m/s*|
|Through fabric surface||Through blowing gap||Through blowing nozzles|
|2,5 [m]||4 [m]||6 [m]|
|*the air flow may differ depending on the static pressure in diffuser|
The standard solution as for the duct shape is circular section. On special request we can also make the ventilation ducts with semi-circular sections and quarter-circular sections.
The standard duct diameters D are included in the series of types [mm]: 200, 250, 315, 355, 400, 450, 500, 560, 600, 630, 710, 800, 900, 1000, 1100, 1250.
Air stream rate in the duct
The maximal useful air speed inside the ventilation duct is reduced to the highest degree by permissible aerodynamic noise dependent on the place of the duct usage. Other restrictions are caused by the flow turbulences that may generate the fabrics vibrations.
The recommended level of the air flow in the duct is presented by the figure:
The length of the single straight ventilation duct series may be from few to several meters depending on the facility dimensional restrictions, material used and the ventilator forcing pressure. The recommended length of the single straight duct series comprises within the range of 2 – 40 meters.
The most frequent solution (the length given in mm):
The particular parts are joined together by means of the zip fasteners. The number of zip fasteners may be adjusted according to the customer’s demand. The total length of the ventilation duct (A + B + C) should be given in the specification. The duct is divided into parts during production, the length tolerance amounts 2%.
The pressure losses caused by the air flow through the fabric duct in the straight sector at the flow speed 6 m/s comprise within the range of 1,5 – 2 Pa / meter. The pressure losses at the flow through the profile (turn, T-connector etc.) are ca. 15 Pa.