Question:
Hello,
I hope you don’t mind me emailing you,
I am contacting you from a Production company in London, we are making a new show all about amazing facts and we are looking into someone beginning lifted into the air. Do you believe if there was enough high speed hand dryers we could lift a average weigh man?
Any help would be fantastic
Many thanks
Naomi H, Researcher
Answer:
Naomi,
What a wonderful and ridiculous question! Short answer: No. But I hope try it, because I would really like to see the footage. What you are talking about here is generating enough pounds per square inch of air power to be able to lift a person. The hand dryer for the job that comes to mind first is the Xlerator. The Xlerator has about as much power as any hand dryer that I can think of that is concentrated in one small opening. The opening is roughly 1 square inch. If you have a 150 lbs man and you try to fit 15 Xlerator hand dryers underneath him, then each dryer would need to generate 10 lbs of force. This would assume that none of the air coming out is dissipated or lost but is efficiently applied to the man.
Now, I don't know how many lbs / inch (or kgs/cm2) an Xlerator can create. But, while I have not tried this experiment on a man, I have done it with a tennis ball. The Xlerator is not so great for supporting a ball in the air because it has one air outlet, but I have taken an Airforce hand dryer, which has eleven air outlets, flipped it on it's back and supported a tennis ball with the air produced. This is kind of fun because as the tennis ball gets away from the stream of air, it gets outside of the range of the sensor and the hand dryer turns off. Then the tennis ball falls back into the range of the sensor, the hand dryer turns back on and the ball goes back into the air. In this way, it can keep balanced and it seems that the Airforce is giving just enough force to keep the tennis ball in place.
A tennis ball weighs 2.1 ounces or 0.13 lbs. I am pretty sure that the Airforce could support about twice that weight, but not much more. So the Airforce has a capacity of about .25 lbs / sq inch. (I hope I don't have to tell you how rough and unscientific this is. The actual force will be different and maybe some day we can do more experiments or calculations to get the exact answer.) I know that the Xlerator is more powerful than the Airforce. I am going to guess that it's 25% more powerful, but let's say for argument sake that it is twice as powerful, or 0.5 lbs per square inch. Then I would need 300 Xlerator hand dryers to support the weight of my 150 lbs man. I could imagine that 300 Xlerators might just do the job. But there's a problem. I can't fit 300 Xlerators under a man. So your answer is no. But don't despair. You can still go to a sky diving experience location where they put super powerful fans underneath the person and they are able to generate enough force to hold them up.
HDE