Fan Life Expectancy

When developing a new electric product, the designer does not have enough information while selecting the proper fan. The spec sheet is not clear on the lifespan of the part. Typically, an engineer can expect a useful life of 50,000 to 70,000 hours running in normal conditions. Real-life will be shorter if the unit is under environmental cycles.

The large majority of fan failures occur due to the motor insulation or the ball bearings, where the bearing life is affected by temperature and speed. Bearing failures occur very frequently compared to motor insulation breakdowns.

The life span specified in the data sheets is a likelihood of survival calculated as the average recorded over a large quantity. It is necessary to understand the conditions used to determine this statistical value.

L10 as a probability Factor
The probability factor indicates the percentage of fans that fail after the period defined from the number of operating units.
The L10 is a statistical figure determined by observing a larger quantity of operating units where 10% of running fans fail and 90% of the same population will survive.

MTBF (Mean Time Before Failure)
Many manufacturers will rate a 200,000-hour life by referring to MTBF rather than the L10 factor.
MTBF is for an exponential failure rate, the time where 63.2% of a given group of components has failed. In the case of fans, it refers to the L50 factor. That is to say that at the end of the declared life expectancy, at least one-half of a given population will have failed.
The difference between the two types of estimates is the calculated failure rate. 

For any inquiries, please contact us at

Conformitec Inc.

4998 ch. Du Souvenir,

Laval, Quebec, 

H7W 4L7, Canada

Tel.: +1 (514) 261-3714