Gauze Attenuation — Fire Attenuation Screens

Determine the radiant heat flux transmitted through a woven wire fire attenuation screen, and the temperature the mesh reaches, using the Stephen Grubits & Associates Gauze Attenuation Model.

Results are for a single layer of gauze and for radiation RECEIVED by the screen. Fire attenuation screens are not a deemed-to-satisfy method of protecting an opening under BCA C3.4, so an Alternative Solution report is still required for the specific building. The 25 kW/m² check shown is the non-piloted ignition threshold used by Verification Method CV1.

Exposure
kW/m²
Radiation arriving at the exposed face of the screen — from BCA Table CV1, or from a heat flux calculation for the design fire.
°C
Air temperature around the wires. Use the outside air for a boundary exposure; the appraisal report used the average furnace temperature when validating against the CSIRO test.
Screen
mm
0.9 mm for the appraised 304 stainless steel mesh. In millimetres — not metres.
wires/inch
Strands per inch in each direction. The appraised mesh is a 10×10 square weave — 394 wires per metre, 42% open.
0.9 for a black powder-coated finish. Bare stainless steel is nearer 0.1 and re-radiates far less.
W/m²·K
Convective loss from the wire surface. 15 W/m²·K is the value used throughout the appraisal report.
Drenching holds the mesh below the boiling point of water, which collapses the re-emitted component. Stated in the appraisal report but not backed by a published worked example.

Enter your values and choose Calculate. Your results will appear here.