Re: Help with 12V air compressor, please.
the vacuum is measured in pascals, or more crudely inHg (inches of mercury) rather than psi.
achieving a 29 inHg vacuum is fairly easy, but i would think the pump and measurement equipment to effectively achieve the vacuum-pressure necessary to transfer the helium from the balloon to the tank would far outweigh the savings. also, i believe the result would be an equalised pressure considerably less than that of the balloon.
thinking back to the use of the vehicle, you can install a compressor (like an a/c compressor) which will run off of engine power. tire service trucks often use them, but i imagine they'd only be capable of <150psi.
R~
found 'em:
http://www.vmac.ca/index.php?underhood
http://www.vanair.com/underdecks-c-4_152.html
