ie8 fix

Want a cooler building without cranking the AC? Stop being colorblind about your roof

By | July 23, 2010, 9:30am PDT

When I was growing up on the east coast, there was this silly rule about wearing white in the summer. Except it really wasn’t so silly, because lighter colors are shown to help reflect hit and keep you cooler when it’s ridiculously hot outside. Think about how blazing hot the asphalt in parking lots can be. How often do you find similarly dark colors around a swimming pool?

Now theories around color are being applied more seriously to rooftops. Most roofs are, quite frankly, dark. Gray, slate, dark green, terracotta. Some materials absorb or reflect heat better than others. Now, a new survey suggests that developers need to be less color blind about there choices. A new Department of Energy study shows that cities could take the equipment of 300 million cars off the road by using white roofs.

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Heather Clancy is an award-winning business journalist with a passion for green technology and corporate sustainability issues.

Disclosure

Heather Clancy

Writing publicly about what the high-tech industry is actually doing to help itself and the world get greener or more sustainable is one way I figure I can contribute more meaningfully to said effort. I am also a big OMG-kind-of-fan of smart leadership, which is why the goodly folks who publish this blog let me go on about this topic and why I am always on the hunt for forward-looking business management ideas.

My daily writing is focused on looking for topics for my blogs, GreenTech Pastures and Business Brains. I also write often about emerging technology trends such as mobile computing, unified communications and cloud computing. Occasionally, I will pop up at an industry conference in some sort of speaking capacity. In cases where a speaking engagement involves a sponsor that may be covered in this blog, that fact will be disclosed in coverage as appropriate.

My corporate writing work usually consists of crafting research white papers about some aspect of technology. In the event that my commentary (in written, audio or video form) mentions a company for which I have provided consulting advice, I will disclose that fact. However, there is no connection between these projects and the topics that I am covering in my blog.

Biography

Heather Clancy

Heather Clancy is an award-winning business journalist with a passion for green technology and corporate sustainability issues. Her articles have appeared in Entrepreneur, Fortune Small Business, The International Herald Tribune and The New York Times. In a past corporate life, Heather was editor of Computer Reseller News, where she was a featured speaker about everything from software as a service to IT security to mobile computing.

Heather started her journalism life as a business writer with United Press International in New York. She holds a B.A. in English literature from McGill University in Montreal, Quebec, and has a thing for Lewis Carroll.

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RE: Want a cooler building without cranking the AC? Stop being colorblind about your roof
EdKett 27th Jul 2010
Techology selection must take into account your current environment; some will work better in your area than others.

White roofs are not a new idea. My parents built a home in Phoenix back in 1962 that had crushed white stone on the roof, large overhangs on the south and west faces, plus used thick hollow bricks filled with insulation. Compared to our neighbors with classical brick and shingle construction, our electric bills were less than half.
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I'm ahead of the curve!
wolf_z 23rd Jul 2010
When I re-shingled my roof 10 years ago I used--polar white! happy
@wolf_z

I'd love to see how that looks.
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re: ahead of the curve
erik.soderquist 27th Jul 2010
@wolf_z

have you noticed an effect on your summer cooling costs?

on the flip side, have you noticed an effect on your winter heating costs now that you are reflecting away potential free heat?
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Correction to your text
TxM2xTx 23rd Jul 2010
Hi Heather

Small correction to your text. You typed "A new Department of Energy study shows that cities could take the equipment of 300 million cars off the road by using white roofs." whereas the actual URL you're linking to mentions "... equivalent of 300..."
@TxM2xTx the entire article needed to be proofed.
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Yes, in the summer.
frgough 23rd Jul 2010
But then you lose solar heating from that nice black roofing in the winter.

But, of course, if the goal were to make energy cheap and abundant instead of telling everyone they have to change their lifestyles we wouldn't have this problem. Oh. Wait. The whole purpose is to give the ruling class a tool to guilt you into servility.
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It's well known that black will absorb heat quicker. But it will also radiate that heat out quicker. So when things cool off the black will get cooler quicker.

At night the black roof will radiate its absorbed heat out quicker than a white roof. Which leads to a cooler building at night.

In the summer you may want that white roof but come winter you want that black roof for solar heating.
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@itguy08

that's not been my experience with asphalt and concrete driveways....

after a bright sunny day the asphalt driveway has still been hot to the touch just before sunrise while the concrete one was quite cold a couple hours after sundown
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What a concept!
Dorkyman 23rd Jul 2010
Tell you what: why not let people paint their roofs any darn color they want, and let them pay more if they use more electricity and less if they use less? Or would that conflict with the "we know better than you, so we will set the rules" crowd?

Next thing you know they'll be telling us to turn off the water while brushing our teeth.
However, (always that, isn't there?) mixed metal oxide pigments are meeting use in much cooler coatings because of their high infrared reflectivity. Mostly we're talking about the baked coil coatings used in metal building products but there is no reason you can't have dark colored IR reflective coatings in the consumer markets as well. The color range isn't as extensive or bright as with most conventional darker pigments, but it isn't bad either. You might look into this technology and do an article on it sometime.
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thoughts
CobraA1 23rd Jul 2010
"Now, a new survey suggests that developers need to be less color blind about there choices."

How about being less blind to "there" grammar ;)?

"A new Department of Energy study shows that cities could take the equipment of 300 million cars off the road by using white roofs."

How many cars would be put back on due to construction costs, I wonder?

Probably have to do it slowly to be able to recoup the costs.

And we're gonna have to spend some time researching what light colors work best with different house colors. I imagine pure white isn't gonna work on everything.
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Might want to correct that.
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Since the snow will melt faster on sunny days. Same as a dark colored road and driveway will melt faster, leading to safer conditions.
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re: darker roads
erik.soderquist 27th Jul 2010
@aep528

asphalt tends to be very slippery when slightly wet... based on living in Michigan and driving on both asphalt and concrete in the winters here, i'll choose concrete every day of the week, wet concrete retains much more of its traction then wet asphalt, and they seem to thaw and dry at the same rates unless you actually have clear ice, which is a rarity. usually you will have packed snow, which does all its own light reflection long before the light can ever reach the road surface
There should be their
Hit should be heat
Equipment should be equivalent
300 million seems a tad optimistic

Who does the proofreading for these articles?

That said, not a totally horrible idea, just needs more study.
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It is such a short article and, in fairness to this author, I am appalled that almost every article I read contains them. Whatever happened to professional proofreading? Frankly, it's scary.
@AZEducator While the "blog" boom has created an outlet for many more people to write, it hasn't given them immediate intellect about grammar and word usage. Sadly, the more opinions you see, the more mistakes you will find. The real hitch is seeing past those to the nuggets buried within.

I agree that your assessment of the standards of proofreading have definitely gone slack, and would love to see more people "using their words" correctly.
Techology selection must take into account your current environment; some will work better in your area than others.

White roofs are not a new idea. My parents built a home in Phoenix back in 1962 that had crushed white stone on the roof, large overhangs on the south and west faces, plus used thick hollow bricks filled with insulation. Compared to our neighbors with classical brick and shingle construction, our electric bills were less than half.

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