What is the smallest helium balloon that could lift an average human?

I am trying to figure out a way to lighten a load with helium balloons. I am looking for a way to make them portable too, i.e. to be carried in a backpack. Is there a more readily available gas that will do the same job without blowing up, or is helium the current best bet?

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bwrussell5 years ago
This was a good thought but I think some sort of mechanical stabilizing system, maybe that attaches to the waists of the people carrying the stretcher, would be better suited. You're never going to be able to get 100m3 of pressurized helium into the mountains, the cylinder alone will weigh just as much as the person you want to carry out, not to mention "Pack it in, pack it out". This will slow down the rescuers putting the victim's life in more danger than a bumpy stretcher ride out.
FoolishSage5 years ago
I think the mythbusters tried lifting someone with helium. I dont recall the exact amount but it was ALLOT of HUGE balloons.

Just to give you a rough idea, 1 cubic meter of air weighs about 1kg, 1cubic meter of helium weighs about 0,3 kg. This means that each cubic meter of helium creates lift of about 700 grams. Lets say a average human weighs 70kg (for ease of calculation) then you need 100 m³ of helium. Don't forget that helium needs to be inside something and that something will also have a weight. If it is under pressure (like in a balloon) it will have less lift and the higher you go the less the outside air will weigh and the less lift your balloons generate..

jemb29 (author)  FoolishSage5 years ago
Thanks!! It's an idea for mountain rescue stretcher teams, to help with lifting and stabilising of a patient over rocky terrain.
I think by the time you need to call in Mountain rescue, you're in enough trouble before some idiot straps you to a 100m^3 balloon.....Especially in the wind conditions MR come out in.

We had a man in LA lift himself in a aluminum garden chair and a BB gun to
shoot out balloons as a descent control.
His antics crossed take-off patterns in LAX and was considered a terrorist
for his stunt.

A 'K' sized cylinder (60" tall by 9.25" diameter) will hold over 100 cubic meters of helium but weighs in at 110 lbs. If it takes about 100 cubic feet of gas to lift the person then you will either need 1x 16 foot weather balloon or many smaller ones. The balloons themselves will only weight a few pounds. Its just a matter of getting the gas hauled in. Not to mention the area the team is moving the person through can have no tree cover. If thats the case then its better for the patient to be air lifted by chopper.
jemb29 (author)  mpilchfamily5 years ago
It is almost entirely low scrub in the area I am thinking of, thanks for the advice!