Re: ambient preferences

[Rick Lucertini <empiricus@sprint.ca>]

Alex Wolfe wrote:

>   Nathaniel- Thanks for the input!
>
>   You're right.  The air consumption issue is a huge one that's been
> bugging me.  Does anyone have figures on the amount of ventilation
> required for a dead space of given size with a normal sized adult male
> of typical respiratory function?  I know that's a heck of a lot of
> airspace and the ventilation alone will be quite wasteful.  [snip]   As
> such I was considering a medical/aircraft type mask for use internally
> to help with ventilation.

Hi, Alex - I think you're looking in the right direction.  That's what I'll be
using.  An oral/nasal mask keeps the flow to a minimum.  As a matter of fact, a
demand reg with an oral/nasal mask would be ideal.  Eliminates jaw strain and
headaches from holding a reg between your teeth in the air, ala Markham.

One problem I can anticipate is increased moisture from exhalations.  The cockpit
will gradually become pretty humid.  Fog on the windows anyone?  Exhaust lines from
the mask to the canopy or external bulkhead would eliminate that problem.  One way
valves - check valves - would have to be installed in the exhaust lines because of
the inevitable partial vacuums in the cockpit.

> A semi-wet or wet design would certainly help with the air
> consumption upon depth change, but I'm not sure being flooded up to the
> chest would be much different than a dive sled with an air bubble to
> pop your head into.  Has anyone else wrestled with and conquered/built
> a dry ambient pressure vehicle?

Ref.: my previous posts this evening . . .  Kent Markham's Popular Mechanics design
was a great idea.  But, that bubble kind of bugged me a bit.  That's how I came up
with the kayak sock serving triple duty:  (a)  volume reduction  (b) "hard tank"
buoyancy control - NO changing buoyancy at all with depth changes   (c)  complete
dryness.

Rick



--
Rick Lucertini
empiricus@sprint.ca
(Vancouver, Canada)