"Existential Angst" wrote:
Awl --

Recently, on one of these How They Do It ditties, they featured but more
Dubai profligacy, this time indoor skiing in the middle of the effing
desert.

The key to the insulation, they explained, was a huge air gap, asserting
that air -- caveat: trapped non-moving air -- was among the best
insulators.

First, is this true? Before I insulated my roof, that air would become
blisteringly hot, and it didn't seem to be moving much. That attic seemed
like a pretty good air gap to me, and it didn't seem to be doing much
insulating.

Second, I seem to remember one strategy where push/pull fans were used with
air gaps in a roof-type situation, to keep air flowing, to reduce the
heating transfer, like what accumulated in my attic -- ie, the exact
opposite of static air.

Now mebbe air behaves differently in conduction vs. *radiant* heat from
roof-type situations that is making the attic so hot, not hot air itself --
if the two can be distinguished wrt air.

iirc, the Dubai ditty used reflection, insulation, AND that big air gap.....

But I've read about this insulating property of air before, so I'm wondering
how it might be employed in a house.
It would seem that if air itself was so good, solid insulation wouldn't be
so high a priority

I wonder what mooslims think about Dubai.....

Vacuum is best, with two reflective sides. I never figured out argon a
heavy gas. I think air with humidity is worse than dry air.
Syrofoam is a little bit worse than some other foams. I could never figure
that out.
Fiberglass tends to be a little worse than cellulose because cellulose
stops air flow better.
I also think extra thin fiberglass is better. Corning used to make very
fine, no itch.
Insulating the roof will shorten the life of shingles, they get hotter.
Maybe if every building had reflective or plants, the world would cool
down.

Maybe someday I'll install reflective sheeting on the house like I did on
garage. First I need to cut openings in the wooden sofet where they
installed perforated aluminum over the wood. Well they did drill a couple
holes in the wood, here and there. Bought the house like that.

Greg