3 replies to this topic

[dylant]

What is the difference between FD and ID Fan?
When are they used? Can we replace them with air blower?

[JoeWong]

What is the difference between FD and ID Fan?
When are they used? Can we replace them with air blower?

dylant,

Suggest the following...

FD vs ID

Basic of Air cooler & Comparison of Induced and Forced Draft Units

JoeWong

[Art Montemayor]

dylant:

Joe has furnished you with an excellent example of how Induced or Forced Draft fans are applied to air-cooled heat exchangers.

Before they were applied to air-cooled units, Induced or Forced Draft fans were applied to Boilers for furnishing combustion air and they still are, to this day. They will probably always be optional methods for boiler combustion air source. I've used the combustion air fan on boilers both ways - induced or forced. The combustion calculations for the boiler are very different as I remember them - specifically with regards to pressure drops and the capacity of the fans.

Maybe you are referring to an application other than air-cooled heat exchangers or boilers, but you haven't mentioned it. Cooling water towers are also equipment that can be installed with either forced or induced air fans.

[dylant]

Joe: Thanks for the links. You are really appreciated.

Art: Your knowledge is undoubtable. I was looking at a charged heater and this heater is using both Induced and Forced Draft fans. Pardon my lack of knowledge cause I have never seen these devices. But judging from the set up, I assumed they are used to pull the air from the atmosphere for combustion purpose and I immediately thought of air blowers. Could you furnish me with more explanation on the boilers?