Fan Power Consumption/Efficiency

[tigerstyle]

Hi there,

I've read the following page (

http://www.engineeringtoolbox.com/fans-efficiency-power-consumption-d_197.html)

and want to use this formula for some further work, as in my test, fan power and pressure are things I can measure, I then plan to use this info to calculate airflow. The formula looks legitimate and quick testing shows it works in my application.

I can't find another reference or source for this equation though? Measuring fan current to calculate for airflow, nothing else on that subject?
Am I searching for the wrong terms, or looking in the wrong places, I'd like a source to verify the equation and maths etc and do some further reading on. Other methods of pitot tube etc are very well explained.

Many thanks.

 

[dbill74]

That page looks like some derivative of the fan laws. They are also generic, and as noted on the page itself,

Note! For detailed engineering - use manufacturers specifications for actual fans

Check out Cook Fan's Engineering Cookbook, page 2 has the fan laws.

Each fan is different with different performance curves. Also affecting a fan's performance is the distribution system to which it is attached. The best way to find the airflow being delivered by a fan is through direct measurement of the airflow.

 

[willard3]

Read and understand the Fan Laws.

 

[HVACMech]

ASHRAE

 

[urgross]

http://www.ftguide.org/ftg/index.htm

 

[FanAirCo]

In most cases you determine Airflow requirements first, based on the type of application you are dealing with, than once you know the quantity of Air that is required you need to determine the resistance to the quantity of air you are moving in terms of Total Static Pressure. Once the Volume and Total Pressure are known then you can select an appropriate Fan or Blower and Motor.

If you need to determine the Airflow from a existing Fan when AMPS and Pressure are given or known, without performing any Airflow tests, it would be best to measure the Fan Speed RPM and contact the Manufacturer with the Fan Model and get a Performance Curve or Performance Table on that specific Model. Only then can you be sure the Airflow is correct. If we can assist you any further please visit

http://www.fanair.com/