Posted by Wayne on July 06, 2001 at 07:28:05:
In Reply to: found this article in 'underwater magazine'... posted by kelphead on July 05, 2001 at 23:31:51:
I mean I guess it makes sense for them to not show the overall thermal picture as they are creating demand for a new product.
But the pressure reduction causes the gas to absorb heat from its surroundings. That is why the metal parts get cold, and why they successfuly got ice to form around the 1st stage in thier test. The more gas flow, the more cooling. The better the heat transfer, the warmer the air.
I have noticed that the air we breathe while diving does not form frost on our teeth. That is because the heat was absorbed from the water surrounding the 1st stage of our regulators and the air stayed cool, but not cold.
And then that reflex to stop us from breathing frozen air! I like to Snow Ski. At Mammoth you can ski in air that is -40 (F and C). When you breath air that cold, you can feel it! But it has never made my larynx spasm closed!
OK so do I believe that it is better to breath warm air? Yes. Do I think that cold air from scuba contributes to heat loss in diving? Yes. Do I feel more afraid because of the writeup? No. Do I think it was one-sided marketing hype? Absolutely!
Wayne