Cooling an island 3

--- In spacesettlers, Ian Woollard wrote:

> Ok. Idea for cooling an island 3.

I could get into this.

> Much as on the earth, the sunlight shines on the ground and the
> ground heats up. This causes convection currents that rise up
> towards the axis.

Yep. Probably some weird swirling from coriolis.

> Ok, now assume the end caps are shielded from direct sunlight.
> (Thin aluminum shield spaced away at the sunlit end, other end is
> fine.)

Any reason it has to be aluminum? Iron is more abundant.

> If you do that, they will be cold, therefore any hot air from the
> central axis will cooled there and sink. So there would be a
> convection cell set up, going from the hot rim, to the axis, and
> then it will get sucked to the end cap where the air will cool and
> spiral out to the rim.

So there are breezes, mainly from the center of the vallyes to the
endcaps... no, wait... only at altitude do you have that, right?

At ground level, you'd have... um...

> At the rim around the end cap you arrange for there to be funnels
> that catch the cool air and pipe it longitudinally along the
> habitat, so that the whole habitat shares the cool air through
> distributed vents.

Perhaps these funnels could be incorporated into the endcap
mountains.

> The pipes are under the floor of the habitat- out in the vacuum
> (incidentally they can be used as a transportation system as well).

Pnuematic tubes. Cool.

> Ok, now the cooling isn't enough- the end caps aren't big enough.
> So, the pipes (which are outside the habitat) may well need extra
> vanes that are end-wise on to the sunlight, and hence they will
> dissipate heat- the amount of distributed heat by the pipes and
> the vanes is proportional to the area of the habitat; so the
> solution scales with the size of the habitat.
>
> The only issues I can see is condensation. Still, most of that
> could happen at the end caps and you can arrange for that to be
> collected and be put back into some lakes. You'd certainly want to
> ensure that the air pipes don't freeze up though.

I'm sure there are wonderful ways to keep that air very, very dry.

> Comments?

I like it. How much temperature difference can you have? IOW, can
you have snowboarding in the endcaps and skinnydipping in the
valleys?

Xenophile (who thinks you can do both on the Big Island, but who has
never actually been to Hawaii, so... ;_; )