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Five Great Reasons to Control Your Fan

 Are you running fans for ventilation or cooling? Do you want to save money and energy?  

Who doesn't?

Many applications running today use single speed fans running at maximum power. Sometimes, the fan may switch on and off based on the temperature sensed by a thermostatic switch. More complex systems may feature multiple fans switching on in sequence as the heat load on the system increases.  Known as sequential or stepped control, this method still runs the fans at their full operating speed.









In these applications, the conditions are ideal for employing variable speed control. Variable speed control is an ideal method for matching the delivery of air with the demand of the application.  By controlling your fans and not running them at full speed, you will be able to provide exactly the right amount of cooling or ventilation for your equipment, while providing real benefits in energy consumption, time between failures and whole-life costs.

Here are five key benefits to using variable speed instead of a fixed speed design fan:

Power Consumption

A fixed speed fan will always consume 100% power when switched on. Using a variable speed fan the power consumption when the speed is reduced by 20% will save 50% of the power to run it. If the fan speed can be reduced by half it will be drawing 1/8th of the power it will consume at full speed.


Reducing the speed of the fan will also reduce its noise level. Reducing the speed by 20% will result in reducing the noise level by approximately 5dB. If the speed can be reduced by half the noise level will be 15dB lower than the fan running at full speed.

Life Expectancy

Running at full speed a fan will draw the highest power and have the greatest power dissipation which means its motor will be running at its hottest. This primarily affects the grease in the bearing system which is the component with the shortest life expectancy. Running the fans at a reduced speed with create less heat which will extend the life of the bearings and the longevity of the fan. A longer lasting fan means a greater interval between service intervals saving on the cost of a replacement fan and the labour required to replace it.

Condition Monitoring

Using variable speed fans with a controller which can compare the fan set-point with the actual performance data can trigger alarm outputs and/or emergency operation modes based on if the fan has failed or is wearing out.


Being able to communicate with the fan via its controller allows flexibility of operation tailoring the cooling or ventilation system according to current needs.

So, whether saving energy, prolonging the life of your equipment or reducing downtime due to equipment failures, variable speed control has the potential to save money. For a great range of control systems, compatible fans and accessories from ebm-papst that could save you money, take a look at the RS Components website today.

Connector Geek is Dave in real life. With over 26 years in the industry, Dave likes talking about connectors almost as much as being a Dad to his two kids. He may still be a kid at heart himself...

18 May 2017, 13:40