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CMiYC writes: "The New Scientist has a short story on a new kind of paint. In the winter it'll make your house darker to heat it up and in the summer it'll might your house's color light to help cool it down. For the best effect your house would have to go from black to white, but I don't know many people that would like their house to be black... Kind of gloomy."
what if they only did the roofs like this. that's where most of the sunlight's hitting anyway.
That reminds me, don't they have that in Sweden? (where they have *everything*, including many, many sets of sexy, blonde, big busted, blue-eyed, twins, triplets, and quadruplets)
Yeah, it was like some deal where the roof was arranged in a staircase-like shape, and the tops were white to reflect high-angle summer sun, and the sides were black to absorb low-angle winter sun. . .
These are my friends, See how they glisten. See this one shine, how he smiles in the light.
Having lived in a cold climate I can assure you that a dark house in a cold winter is every bit as helpful as a light one in a hot summer is.
Furthermore while a blacktop road can be stifling in summer it can also shed itself of snow & ice faster in the winter. I spent 2.5 years living in a small farmtown north of Montreal by the foot of the Laurentian Mountains: One quickly learned which parts of which roads would be clean & dry after some solar heating and which ones would remain treacherous. New & dark roads cleared quickly, older & bleached would take much longer.
Finally the paint-the-roof-white studies focussed on cities in the US West. These are primarily flat roofs covered in black asphalt & yes it was determined using some sort of cheap white-wash on top would significantly reduce both heat transmitted to the structure & heat contributed to the local environment.
On the other hand places with colder climates tend to get more precipitation and have fewer flat-roofs, particularly places with heavy snow buildup. There roof-color is less significent as other effects like angles & extensive attics come into play. It's not a matter of a dark roof being intrinsically less effective, it's just there are more variables to affect their performance.
I don't read ACs: If a post isn't worth so much as a nom de plume to its author then I wont bother either.
This is not a technology that will ever see the outside of more than a handful of houses.
- Many people (I'm not one) care about the actual color of their houses. They can spend hour poring over books of paint chips. Having a house constantly change between a couple probably ugly colors will be completely unacceptable. What color do you paint the trim?
- While having a house that's not dark in the summer will help quite a bit with cooling, the actual heat absorbed by a dark color in the winter would be minimal.
I don't have any references, but I recall reading about getting city buildings to paint their roofs white instead of black to reduce the urban heat island effect. It was stated that it wouldn't make much difference in the winter for keeping things warm.
Also, consider how hot black asphalt gets on a sunny summer day. Now consider how hot it gets on a sunny winter day when the temperature is 0.
It's conceivable that this paint could find applications, but I don't it's going to be anything like energy efficient houses.
The Math Maestro Tutoring Services in Seattle
Wouldn't it be cool to paint this stuff on the toilet seats at work? Then you could tell how long it's been since it has been in use. I hate sitting on a warm seat.
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CAIMLAS
~/ssh slashdot.org ssh: connect to host slashdot.org port 22: too many beers
Doesn't California have a tax incentive? Something like 50% deductible?
And it's not cost effective if you expect power prices to remain where they are. Market fluxuations will be in your favor!
And if your goal is an energy efficient house, you can buy a modular house for the SAME cost as a regular house. Only difference is that your power bills are 1/10 to 1/4 of what they used to be.
Power companies HAVE to accept the power you add to the grid and reimburse you. However, unless you've got a megawatt reactor in the basement, you're not going to get much.
Once the government stopped subsidising renewable energy in the 80's, the field has settled down and has made some impressive strides. Windmill generators have become more efficient, solar cells have also become more effective, you can buy a micro geothermal plant!
Democrats or Republicans. They are both taking us to the same place and they are not afraid of us anymore.
For places with real snow winter, you're probably right, but bear in mind most of the world lives in warmer climates.
If winter means +10C and summer +30C, I think this would work just fine.
I hope the colors aren't fixed to certain temperatures (80deg -- red, 100 deg -- blue). If the stuff catches on, it will be like a psychadelic housing tract. However, if it got popular enough cities would look a lot like a weather maps from the air :).
just my blog and pix
Very true. In fact, black (i.e. Flat Black) is not the most efficient absorber of solar energy (contrary to popular belief).
Back in the mid to late 70's when solar energy was at the forefront, I conducted experiments using various color solar panels (regional science fair competiton). My results were in line with the published material of the day...the most efficient color was flat leaf green.
When coupled with a laminar flow (rather than copper tubes) and non-UV absorbing glass, those collectors really worked well.
The following year I build a model solar home equipped with thermostats, a thermal storage tank (filled with eucletic salts) and automated skylights (not bad for a 9th grade experiment).
While I didn't win the competition that year in my category, I did discovery that the design of my solar home was highly earthquake resistant and it slid of the bus seat and wedged itself between seats after the competition. Also discovered that the space between school bus seats is actually very small as it took over an hour to extract my model home. Thought about that for the next year's experiments, but instead settled on a optical digital data transmission.
I heard a couple years ago that NREL (National Renewable Energy Lab) was working on amourphous silca (photovoltaic) shingles that were tied together electrically by nailing through a copper band on the underside of the shingle. The idea was that you'd just reshingle every house in America with these things.. I don't know exactly what happened with that project..
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crazy dynamite monkey
Also, if your house is well insulated, it will do just as well at keeping that sun-induced heat from your dark exterior out as it does at keeping your central heating heat in.
Quattuor res in hoc mundo sanctae sunt: libri, liberi, libertas et liberalitas.
Okay, now what would the building committe think about this? They get upset enough when I try to paint my house _one_ color!
"Evil company X is threatening to restrict our rights! Let's all get together to stop--OOOH! SHINEY!!!" -- AC
What's important is if it's light or dark, correct? So choose what color you want, and then it will go from (say) midnight blue to sky blue.
The only "intuitive" interface is the nipple. After that, it's all learned.
"The question of whether a computer can think is no more interesting than that of whether a submarine can swim" -EWD
This reminds me of an engineer acquiantance of mine. He designed the most energy efficient house in Canada. It had solar panels, double-paned windows with a hollow wall between them and the outside, an ultra-efficient heating system, the works. It WAS the most energy efficient house, anyhow.. After a year, the tenants got so depressed looking at the energy efficient black paint that they painted it a nice light blue.
I think I can still hear the engineer gnashing his teeth about it..
...find a home painted in this stuff, and write obscene things on it with a low power laser, water pistol, etc.
...take a pic of same house on a normal summer day, go to paint store, get custom paint, come back and grafitti house liberally. Invisible today, pretty dramatic when winter comes around.
...get a stepladder, press butt or other anatomy against middle of front door, ring bell, run.
-b
If I wanted a sig I would have filled in that stupid box.
Maybe on Election Day in the U.S. it could automatically change to Red if you're in a GOP kinda mood or Blue if you're voting for the Dems.
That way the networks could use satellite images to figure out which states are going for which candidates. No more premature victory predictions!
I don't know many people that would like their house to be black
It wouldn't have to be. Why not just paint the roof, which on slate houses is near-black already? After all, the sun *is* above us, in the sky.
Michael
...another comment from Michael Tandy.
"Goodness me, how unlike the FBI to abuse the trust of the American public." -- The Onion
to dropping acid and seeing colors
Unless your furniture change colours too, this will be a major headache to all interior designers.
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Codeala - Just another mindless drone
I can see it now! Battle damage 4 bedroom homes. Temporary obscene graffiti by kids with ice water in their super soakers!
Emotions + Paint = Emotaint (pronounced E-moe-shaynt)
IMHO I would be highly upset to bring a chick home thinking my house was white when I left, and black and morbid (d(a)emonic) looking when we got there.
you big pimp you
360 degrees of Karma