Adding a nacelle in front or behind the fan?

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4 replies · 2K views
boeing186
Can adding a nacelle in front or behind a standard pedestal fan affect the speed of the air coming in and out? If so, which is more beneficial: an intake nacelle or a nacelle in the front?

Using Q=AV, with Q being constant because of the fan blade's max speed, can affecting the area (A) create a noticeable difference in velocity (V)?
 
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boeing186 said:
Can adding a nacelle in front or behind a standard pedestal fan affect the speed of the air coming in and out? If so, which is more beneficial: an intake nacelle or a nacelle in the front?

Using Q=AV, with Q being constant because of the fan blade's max speed, can affecting the area (A) create a noticeable difference in velocity (V)?
Welcome to PF!

It is difficult to know for sure and depends on exactly what you want to do with the fan. The general answer is yes, but there is a cost. Any restriction added to the fan will reduce the fan's airflow. So if you are OK with reducing the airflow to increase it's velocity, you can do that.
 
russ_watters said:
Welcome to PF!

It is difficult to know for sure and depends on exactly what you want to do with the fan. The general answer is yes, but there is a cost. Any restriction added to the fan will reduce the fan's airflow. So if you are OK with reducing the airflow to increase it's velocity, you can do that.

Thanks! And I see. So in fans used for cooling, is a decrease in airflow but an increase in velocity more beneficial than the other way around? And if so, is there a limit to this or an equation that I can use to find such a relationship?
 
boeing186 said:
Thanks! And I see. So in fans used for cooling, is a decrease in airflow but an increase in velocity more beneficial than the other way around? And if so, is there a limit to this or an equation that I can use to find such a relationship?
That would depend on the type of cooling being done.
 
russ_watters said:
That would depend on the type of cooling being done.

Sounds kinda stupid, but cooling myself up to two yards away
 

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