How many cfm can a typical hair dryer blow?

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- mrdarrett
  
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posted
14 years ago

Thu, Jun 26, 2008 4:15 PM

I think it's somewhere between 10 cubic feet per minute (cfm) and 100
cfm, but can anyone give me a more precise value?
Anyone have a hair dryer manual, a link to specs, ???
Thanks,
Michael

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- Cwatters
  
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posted
14 years ago

Thu, Jun 26, 2008 5:11 PM

If you know the wattage of the hair dryer and you can measure the temperature rise you can work out the cfm easily.
Google "specific heat capacity" or see...

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- Uncle Al
  
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posted
14 years ago

Thu, Jun 26, 2008 5:17 PM

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Pat. 4230279

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go turbo
We live in a Golden Age raining soup and you complain about all the yellow while using your soup bowl as a rain bonnet.

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- Spaceman
  
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posted
14 years ago

Thu, Jun 26, 2008 5:43 PM

??? He is asking for cubic feet of air isn't he? Why bother with heat at all? To get a roundabout figure. Place a plastic bag that holds ten cubic feet of air or larger, tape the bag around the output nozzle. turn on and time the fill rate til it is full and stop your watch. That will give you 10 cubic foot per "time" or whatever size bag you have per time. do the easy math to convert to cfm.. :)
Be sure you have it on "cold setting" if you have it on too long. or be sure to be carefull enough to not melt the bag if only hot is available. Gotta love physical experimentation and basic math. It is way more fun than "math only stuff". :)

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- mrdarrett
  
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posted
14 years ago

Thu, Jun 26, 2008 5:55 PM

Trash bag... great idea. I never thought of that. I was thinking of a Ziplok bag, and measuring for < 1 second... not too accurate...
Thanks,
Michael

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- Spaceman
  
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posted
14 years ago

Thu, Jun 26, 2008 6:14 PM

No prob, have fun and of course. never be stupid, but crazy is OK. :)

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- mrdarrett
  
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posted
14 years ago

Thu, Jun 26, 2008 6:20 PM

Ah, I see, I didn't describe the problem adequately. The posted wattage of the hair dryer is kind of irrelevant because I ripped out the heating element from a surplus hair dryer. I discovered the blower operates on 12V, 1A. So it's this cold air I was trying to analyze.
Uncle Al had a good point, use muffin fans instead (one of his sites said hair dryer motors work only for a few hundred hours, vs. thousands of hours for a muffin fan). Muffin fans routinely post their CFM specs. So now I can move on...
Michael

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- Cwatters
  
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posted
14 years ago

Thu, Jun 26, 2008 6:31 PM

Good thinking batman err I mean Spaceman.

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- dlzc
  
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posted
14 years ago

Thu, Jun 26, 2008 6:59 PM

Dear mrdarr...:
=2E..

Remember to check delta-p... they don't do well at all as "vacuum cleaners" or "forced air blowers. The squirrel cage of the hair dryer is better for pressure work, even if the motor is designed to merely outlast the interest of the one that uses it.
How much air do you need to move? What sort of things are you going to expect to do with the air?
"ring compressors" are pretty good, if you need either a mild vacuum or pressure (a few feet of water). Some selections in Grainger.
David A. Smith