How do I know when to use electric or engine driven fans? Do I need a fan shroud? We'll answer these questions and more.

Electric Fans

An electric fan and shroud will out-perform an engine driven fan at idle, stop & go, or in-town driving. These situations are when you need the fan to perform the most. Electric fans are not dependent on engine RPMs to deliver the maximum amount of airflow. Switching from an engine driven to electric fan gains horsepower & fuel economy. 

Automotive & Light Truck Fan Options
  • Standard Performance
    • Fans Under 390 HP
  • High CFM
    • Fans Over 390 HP

The difference is in the fan blade design and the motor size or AMP draw.

Pusher or Puller Fan?

Use a puller fan whenever possible. A pusher fan does not move as much air as a puller. They also interfere with air flow at highway speeds. The experts say pullers are 20% more efficient than a pusher. 

Shrouds

DO YOU NEED ONE?… Yes! Whenever possible. Radiators require air movement to cool an engine. At idle or cruising speed you need the whole radiator working for you. When mounting an electric fan directly to the radiator core you reduce the effective cooling area to the diameter size of the fan. A large percentage of the core is not receiving any benefits of the fan and is not doing any cooling. When you use a shroud, you use the entire radiator core for cooling, as intended. 

Questions to Ask When Selling a Fan Shroud
  • How much horsepower are we dealing with?
  • How much room do you have between the radiator and the water pump or belts and pulleys?
  • Do you have the right wiring harness?
    • High CFM fans require a heavier wiring harness
    • A/C relay override may also be needed (add on)
How Do You Mount the Fan Shroud to the Radiator?

Northern’s fan shrouds mount to the side channels on our radiators. You can attach them by:

  • Self-tapping screws
  • Drilling holes and using a matching nut and bolt
  • TIG Weld
Do Our Fan Shrouds Fit the OEM Radiator?

All our fan shrouds are designed to fit Northern's radiators and not the OEM. Some will fit the OEM, this is just by chance. By checking the measurements, you can easily determine if it will fit the OEM or not.

Key Takeaways:
  1. Generally speaking… an electric fan and shroud will out-perform an engine driven fan at idle or stop & go, in-town driving.
  2. Switching from engine driven to an electric fan gains horsepower & fuel economy.
  3. Use a fan shroud whenever possible.
  4. The difference between standard and high CFM fans are the fan blade and motor size. 
  5. Three questions need to be asked when selling a fan & shroud.
    1. How much horsepower are we dealing with?
    2. How much room do you have between the radiator and the water pump or belts and pulleys?
    3. Do you have the right wiring harness?
  6. A puller fan is more effective than a pusher at maximizing air-flow.
  7. Northern's shrouds mount to our radiators in a few ways:
    1. Self-tapping screws
    2. Drill holes and use a matching screw and bolt
    3. TIG Weld
  8. Our fan shrouds will probably not fit an OEM radiator.
Remember, there is a time and a place for each fan & shroud that we supply.