Changes

==Chemical Hypoxic Generators==

Chemical generators use a chemical reaction to either remove oxygen from the air,or to remove the carbon dioxide from the air that you exhale, which is then breathed again. These systems are cheaper to purchase, but require the ongoing purchase of the chemical cartridges. These systems are only used for intermittent training, not for sleeping.

AltiPower uses a system that removes the CO2 from the exhaled air that is then rebreathed. It is not clear how long the cartridges last, or what altitude is achieved. http://www.altipower.com

* AltiPower Pro Kit, $1,000. Comes with 2 cartridges and Oximeter

* Replacement cartridges $100 each, $300 for four

===AltoLab===

AltoLab uses a stack of AltoMixers, with each AltoMixer diluting the oxygen to provide the equivalent of 5,000 ft. The AltoLab system also requires a CO2 scrubber which has to be replaced and lasts 2-3 hours. The running costs would be $10-15 per hour. http://www.altolab-usa.com/