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Airflow
Posted: Mon May 07, 2007 8:53 am
by Tea_Bag
Hi Guys,
I have a question that needs answering! How do you calculate the amount airflow in a hair dryer (in theory)? If any one could help that would be great!
Thank you
Tea_bag
Posted: Mon May 07, 2007 10:01 am
by Aji Enrico
do you want volume of air, force, speed, efficiency? (I'm guessing volume)
Posted: Mon May 07, 2007 10:28 am
by Tea_Bag
Yeah volume is the one
Got any hints
Posted: Mon May 07, 2007 12:33 pm
by vansan
Just blow the air inside a condom for 5-10 secs, then do the same with another one, but instead fill it with water to the same visual volume. Then measure it's volume.
Simple math calculation - and u've got air flow per minute.
Posted: Mon May 07, 2007 1:34 pm
by Tea_Bag
You make it sound too easy!
Where is that condom.....Ah here its is!
Thanks for the tip will give it ago
Posted: Mon May 07, 2007 5:07 pm
by deadalvs
vansan wrote:Just blow the air inside a condom for 5-10 secs, then do the same with another one, but instead fill it with water to the same visual volume. Then measure it's volume.
Simple math calculation - and u've got air flow per minute.
that must be a REAL HUGE condom !
Posted: Mon May 07, 2007 5:29 pm
by ivox3
Nice science. I can't imagine any physics class doing it any different.
volume test
Posted: Mon May 07, 2007 7:20 pm
by codygo
That doesn't take into account the force of the elasticity fighting against the blower in those 5-10 seconds, maybe a garbage bag would be a better test. I don't even think a hair dryer has can produce enough psi to expand a balloon/condom. What you want is a cubic feet per minute and linear feet per minute rating.
this is from a google search for hair dryer cfm:
http://www.worlddryer.com/airstyle.html
Airstyle Hand Dryer Specification Guide
World Wind Hair Dryer Specification Guide
Cover and back plate shall be made of high impact ABS plastic with flexible hose permanently attached to direct air flow. Unit shall be equipped with 2 speed dry/style switch and shall deliver 50 CFM and 3500 LFM at maximum rated voltage.
They claim the motor from the hair dryer they used puts out 90cfm.
Posted: Mon May 07, 2007 9:49 pm
by Aji Enrico
My math is a bit rusty so if anyone wants to object or correct me please do so.
The way I would do it in theory and practically is to see how far
colored gas
can travel through a transparent tube in a given time. By measuring the dryers
area where air flows through and measure how far it travels in a given time you will know
the volume airflow it produces.
Posted: Mon May 07, 2007 10:44 pm
by vansan
Aji Enrico
Hey, that looks like a big hair-dryer gun.
Hide now, before FBI capture you as a developer of new-generation of massive destruction weapon!
Posted: Tue May 08, 2007 4:23 am
by donb
Don'r worry, Vansan. The Orange tip identifies it as a big 'toy' hair-dryer gun.