1 bar = 750 mmHg = 13.546X750 mmWg = 10,160 mmWg
mmWG is a pressure unit. its something like mm Hg, however in mmWG, W refers to water and G refers to gauge pressure. Hence, mm WG refers to the gauge pressure in terms of milimeters of water.
Fans, blowers and compressors are differentiated by the method used to move the air, and by the system pressure they must operate against. As per American Society of Mechanical Engineers (ASME) the specific ratio - the ratio of the discharge pressure over the suction pressure is used for defining the fans, blowers and compressors. Equipment /Specific Ratio /Pressure rise (mmWg) Fans /Up to 1.11 /1136 Blowers /1.11 to 1.20 /1136 2066 Compressors /more than 1.20 /