DIN 18232-7
DIN 18232-7 Smoke and heat control systems - Part 7: Heat exhaust ventilators made of meltable materials; Assessment procedure and installation
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 02/01/2008
standard by Deutsches Institut Fur Normung E.V. (German National Standard), 02/01/2008