Passive cooling panels beam air conditioners' exhaust-heat into space


#21

“The model showed that cooling a two-story commercial office building in Las Vegas with fluid-cooling panels—which covered 60 percent of the roof—cut the building’s electricity use by 21 percent compared with using only a traditional fan-based condenser during the hot summer months of May through August”.

Wait, wouldn’t the shade provided by the panels keep the rooftop cooler? Thus the entire building would use less energy for cooling, regardless what the panels do? Same principle as shaded by a tree?


#22

Let me guess, hitched a ride with a teaser?


#23

They were thinking about it in the sixties, don’t know if they tried it, to dump heat from a Stirling engine. (It’s easy to keep one side hot with a small mirror, but the other side has to be kept cooler.)

Looks like they did get around to it ~2008:


Ah, this gets heat from radioisotopes rather than solar. It still has to dump heat.


#24

My guess is it could be either…

teas·er
ˈtēzər/Submit
noun
1.
informal
a difficult or tricky question or task.
synonyms: question, problem, quandary, poser
"a difficult teaser to answer"
2.
a person who makes fun of or provokes others in a playful or unkind way.


#25

ARTHUR DENT:
But how did you get there in the first place?!

FORD PREFECT:
Oh easy! I got a lift with a Teaser. You don’t know what a Teaser is, I - I’ll tell you. Teasers are usually rich kids with nothing to do. They cruise around looking for planets which haven’t made interstellar contact yet and buzz them.

ARTHUR DENT:
Ah. “Buzz them”?

FORD PREFECT:
Yeah. They find some isolated spot with very few people around, then land right by some poor unsuspecting soul, who no one’s ever going to believe, and then strut up and down in front of ‘em wearing silly antennae on their head and making “beep, beep” noises. Huh, rather childish really.


#26

But the trick here seems to be emitting radiation in a band which the atmosphere is transparent to. The same issues don’t apply in vacuum, where any old material can be a radiator.


#27

No that would make the panels warmer than the building under them. These panels radiate energy through the atmosphere, so they stay cooler than they otherwise would be. Its a bit like the photovoltaic panels in Heinlein’s The roads must roll but in reverse.

Which gets me thinking…


#28

“Scotty, I need more power!”
“Sorry Captain, but I’ll have to take the Stirling engines offline. On that last attack, we took a bullet in the radiator and we’re all out of Stop Leak.”


#29

Why send energy to space? Why not use it to sequester carbon?


#30

Heat can only generate usable energy if you can create enough differential between the heat source and the surrounding environment to harness it, such as using expanding gases to push a turbine.


#31

Theoretically, you could use a Stirling engine to circulate water to the cooling panels, and then use the water to keep the low temperature side of the Stirling engine cool. Use any excess power to generate electricity.

That doesn’t violate any laws of physics, but it’ll probably bog down in the math. (Endless YouTube videos from the over-unity crowd in 3… 2… 1…)


#32

Correct, but you don’t need a turbine.

You could use Seebeck effect thermal generators.


#33

Please tell me we’re not accidentally cooking any birds flying overhead with this thing?


closed #34

This topic was automatically closed after 5 days. New replies are no longer allowed.