>
> Wood stops burning when the oxygen content falls to 17% and plastic
> cables between 16 to 17%
>
> At 15% oxygen, it's safe for humans to enter.



So the idea is to hold the oxygen content within that 1% band?
Hmm.
-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist