Exhaust fan and quick-opening air damper
Thread Content
Regarding the interlock between the heating furnace exhaust fan and the quick-opening air valve? When the induced draft fan stops, the air inlet valve should be opened. When should the induced draft fan be started during operation? Are there any precautions to take? What about adjusting the negative pressure of the furnace?
When the exhaust fan stops, the blower also shuts down automatically. The quick-opening dampers are opened, as well as the dampers in the flue pipes; this means that ventilation is switched from forced to natural ventilation! At startup, start the induced draft fan first, then the blower! Be careful of the negative pressure in the furnace! Adjust the parameters in a timely manner!
When the induced draft fan stops, the air preheater bypass opens; if it does not open, positive pressure in the furnace is generated, triggering a shutdown sequence. To start the induced draft fan, open the outlet valve first, then the inlet valve