our body temperature is around 34C and air at higer altitudes is very cold. the temperure differential is therefore very large all the passengers have to do is to exhale into gasmasks which are linked together with check valves to prevent inhalation. speech diaphragms as found on normal masks allow communication. excess pressure would be vented off to prevent the baloon from bursting-- giligamesh, Jul 11 2008 GG: a few things. 1 - you have 2 ideas posted that are the same. You can delete one. 2 - Why don't you edit this to make it more clear what you are trying to do. Are you powering your blimp off the temperature differential between the passengers and the outside air, via the breath of the passengers?-- bungston, Jul 11 2008 Don't forget: urine is warm too. One could offer free beer aboard the blimp to enure a plentiful supply.-- bungston, Jul 11 2008 Hope you don't want to go anywhere too fast! I don't think the ballon is gonna burst. Nor Fly. What do we do with the warm breath? What does it power? [marked-for-deletion] No Idea.-- gnomethang, Jul 11 2008 Does the hot air power the movement of the blimp, or just loft the balloon? Either way, the heat available is limited to the amount each passenger can metabolize. And the insulation of the gas bag had best be pretty good. Somebody needs to do maths.
This could be a pedaled blimp, with the passengers heating the balloon with their breath and body heat. But even that is not likely to work.-- baconbrain, Jul 11 2008 Body temperature is around 37°C. Even so, this will never work.-- Texticle, Jul 12 2008 As per the other identical idea, the heat lost from a large blimp has to be replaced by heat lost from the passengers. On that basis, either your passengers are going to freeze, or this blimp will not stay up.-- david_scothern, Jul 12 2008 Coming soon: "Hot air blimp 3" with extra smoke and mirror power!-- xenzag, Jul 12 2008 I don't see the first idea... but why all the negative attitude.
Gili was talking about floating the blimp, not about propelling it.
On a cold day, inside a closed balloon with a thin double coating, so basically air insulated from "cold" (actually the outside is being insulated from the internal heat) CO2 is pushed out of the balloon, slightly depleting the balloon while warming it up, in addition to the body heat. With a large enough crowd the balloon could heat up pretty quickly. If its large enough it could pick the crowd up. No?-- pashute, May 26 2014 I was right! I had a feeling that [teslaberry] had existed here in a previous incarnation.-- MaxwellBuchanan, May 26 2014 random, halfbakery