What You Need To Know About Electric Cooling Fans

Electric Fan

Condenser/Radiator Cooling Fans enhance the cooling system performance and help eliminate overheating and extremely high head pressures. These assemblies are designed to lower engine operating temperatures and lower A/C system head pressures. At the same time maximumizing system performance with colder air and increased passenger comfort especially in heavy and slow moving traffic

What fan do I need to cool my vehicle?

The efficiency of your cooling system depends on the following factors:

Radiator core size (the size of the radiator inside the tanks where the cooling tubes and fins are located.) This space determines the diameter of the fan.
Space required for a cooling fan. Our High Performance cooling fans require 3.5-4.5-inches in depth (from the radiator core to the fan motor cap). This distance may be shorter if the cooling fan can be offset on the Radiator to clear the water pump.
Radiator material and number of cores. An aluminum radiator is more efficient than a copper radiator.
If a shroud is utilized: For the most efficient system a shroud should be utilized. The shroud forces the fan to pull air across the entire radiator core area, opposed to a fan without a shroud that pulls air only across the diameter of the fan.

What is static pressure when talking about electric fans?

Static pressure is basically the amount of restriction in front of, and behind the fan. It’s measured in inches of H20 (water). Some fan companies advertise their fans using the CFM (Cubic Feet per Minute) output at zero static pressure. This means the CFM output was measured without any restrictions. In real life applications, your cooling fan will be moving air through a front grill, AC condenser, radiator. On the back side of the fan you will be exhausting air against the engine and engine compartment. All these factors create static pressure.

What is the normal static pressure range created by a condenser and radiator in an average vehicle?

The average vehicle will have a static pressure of about .5 to .7 inches H2O static loads. Ask for the fan output rating in these static load conditions when shopping for a good fan. A replicable fan manufacture or distributor will have a complete cure chart of CFM ratings, static pressures and amperage demands available for your use. Listed below is a chart showing the general operating range of our fan product verses some of our competitors. As you will see our heavy duty high static load 16 inch fan #17-16VHP-S is much stronger than anyone else in our industry while our high performance 16 inch fan #17-16SHP-S is still equal or more efficient than our competitors. Be careful when purchasing an electric fan, some manufacturers and/or distributors advertise high CMF ratings that are inaccurate and misleading to consumers as shown in the performance chart below. Do not be misled by high CFM numbers at zero static pressure that do not accurately apply to your vehicles actual working conditions.

What about amperage draw?

Large fans can require 20 amps or more to operate. The vehicle charging system has to be capable of providing adequate current for the fan to operate properly. In some cases, larger alternators are required for some of the higher wattage fan assemblies.

How should I control the fan assembly?

In most cases relays and sensors are used to cycle the fan assembly. Before purchasing a fan wiring kit make sure the wire gauge provided in the kit is sized to handle the current needed to operate the fan correctly. Be sure the design of the wire harness circuits the motor amperage through the relay, not the sensor. Most sensors are not designed to handle heavy current. Running high amperage directly through switches and sensors will shorten the life of the components. All fan wiring kits should be fuse protected.