Difference Between ID Fan, PA Fan, and FD Fan – Complete Guide

Difference Between ID Fan, PA Fan, and FD Fan

In the industrial world, especially in power plants and manufacturing units, fans play a crucial role in maintaining efficiency and safety. But not all fans are created equal. If you’ve ever wondered about ID fans, PA fans, and FD fans, this guide will help you understand their differences, applications, and why they’re indispensable in industrial setups.

What is an ID Fan?

ID Fan stands for Induced Draft Fan. Its primary function is to draw flue gases from the boiler and discharge them through the chimney. Essentially, ID fans create a negative pressure inside the boiler, which helps in efficient combustion and gas removal.

Key Features of ID Fans:

  • Usually placed at the outlet of the boiler.

     

  • Works under negative pressure conditions.

     

  • Helps maintain a constant airflow, improving boiler efficiency.

     

  • Can be axial or centrifugal, depending on the design requirements.

     

Applications:
ID fans are commonly used in thermal power plants, industrial boilers, and furnaces to remove smoke and flue gases efficiently.

What is a PA Fan?

PA Fan stands for Primary Air Fan. Unlike ID fans, PA fans supply the necessary air for combustion. They blow primary air into the boiler’s furnace, which is essential for burning fuel like coal efficiently.

Key Features of PA Fans:

  • Supplies preheated air to the boiler for fuel combustion.
  • Maintains optimal air-fuel ratio.
  • Operates under positive pressure, pushing air into the furnace.
  • Enhances fuel efficiency and reduces emissions.

Applications:

PA fans are mostly used in coal-fired boilers and power generation plants, ensuring that combustion is stable and efficient.

What is an FD Fan?

FD Fan stands for Forced Draft Fan. As the name suggests, it forces fresh air into the boiler furnace to support combustion. FD fans are similar to PA fans but are generally used for larger volumes of air at higher pressure.

Key Features of FD Fans:

  • Provides forced air supply to the furnace.
  • Works under positive pressure.
  • Often combined with a boiler’s air preheater for better efficiency.
  • Can be used in coal, gas, or oil-fired boilers.

Applications:

FD fans are used in thermal power plants and large industrial boilers to ensure proper airflow and enhance combustion efficiency.

Key Differences Between ID, PA, and FD Fans

Feature ID Fan (Induced Draft) PA Fan (Primary Air) FD Fan (Forced Draft)
Function
Removes flue gases from boiler
Supplies air for fuel combustion
Forces air into boiler furnace
Pressure Type
Negative pressure
Positive pressure
Positive pressure
Location
Boiler outlet
Boiler inlet
Boiler inlet
Airflow Direction
Draws air/gases out
Blows air into furnace
Blows air into furnace
Applications
Thermal power plants, industrial boilers
Coal-fired boilers
Large boilers, thermal power plants

Why Choosing the Right Fan Matters

Choosing the correct fan type is vital for efficiency, safety, and longevity of your industrial setup. Using the wrong fan can lead to:

  • Inefficient combustion
  • Higher fuel consumption
  • Excess emissions
  • Equipment damage

Working with a trusted fan manufacturer ensures that the fans are designed to withstand industrial conditions, offer energy efficiency, and require minimal maintenance. 

Conclusion

ID fans, PA fans, and FD fans may seem similar at first glance, but each plays a unique role in industrial operations. ID fans focus on removing gases, while PA and FD fans are responsible for supplying air for combustion. Understanding these differences helps industries optimize efficiency, reduce costs, and maintain safe operations.

If you’re looking for high-quality ID, PA, and FD fans, it’s essential to choose a reliable manufacturer that offers durable, energy-efficient solutions tailored to your industrial needs.