wrote:
| On May 8, 6:00 pm, "Morris Dovey" wrote:
|| wrote:
||
|||
http://gizmodo.com/gadgets/notag/sol...-soda-cans-256
||| 740.php
||
|| I got a chance to see the top photo before the paged caused my
|| internet exploder to explode...
|
| it viewed fine in firefox in my "default" mode: no scripts, no
| flash, no popups, most of the adservers killfiled, etc. I had no
| idea that there even was anything explosive on the site. sorry
| about that.

Don't be - it hasn't been nicknamed "Internet Exploder" without cause.

|| The design is OK for a science fair project - but we've made a lot
|| of major improvements since these appeared in the early 70's and
|| this design doesn't reflect (sorry) any of those improvements.
|
| ayup. kind of a toy, but it does demonstrate the right kind of
| thinking.

Absolutely. His/her next will very likely be improved.

|| The design will run too hot, meaning that it'll be unnecessarily
|| lossy from both conductivity and re-radiation in the IR range - as
|| well as the obvious reflective losses (if you can clearly see the
|| details of an absorber, too much of the energy is being reflected
|| back to the environment and isn't being collected.)
|
| now here's what I was kinda getting at: you have the background to
| make real, constructive criticisms. gizmodo is full of people who
| want to learn. you seem willing to teach...

I've become an expert at recognizing the mistakes I've already made.
FYI, there are regulars here who know much more than I about the
science and engineering of these things. I'm just a hacker who's
willing to make one mistake after another until I finally manage to
make things come out right. The people who want to learn deserve
better than an old geezer enumerating the shortcomings of their
design - they need someone who can explain /why/ in terms they can
understand, and I'm sorry to say that someone isn't me.

Building a really good solar heating panel requires knowledge from a
number of disciplines in which I've had no little or no training:
physics, heat transfer, materials, thermodynamics, fluid dynamics,
architecture, etc. ad nausea. The field positively _begs_ for
multidiscipline collaboration.

Most of the people building this stuff think that temperature and heat
are synonyms, that hotter is always better. They choke when told that
_cooler_ is better, and that there's more than twice as much solar
radiation that can't be seen as can be. Some get downright angry when
you tell 'em that /painting/ a collector black is begging the
question, and that what's really needed is to design the collector to
/be/ black (no matter what the colors of its components are!)

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/