HomeLatest ThreadsGreatest ThreadsForums & GroupsMy SubscriptionsMy Posts
DU Home » Latest Threads » Forums & Groups » Topics » Environment & Energy » Environment & Energy (Group) » White shingles, white roo...

Fri Nov 9, 2012, 06:38 AM

 

White shingles, white rooftops, less fossil fuels, less climate impact.

http://www.ehow.com/about_6756345_light-shingles-vs_-dark-shingles.html



Whether re-roofing or installing the first roof on a new home, one important consideration is color. Along with roof texture, roof color is a major aesthetic component of a building. However, for many consumers appearance may be trumped by energy conservation in these days of green construction. National Geographic reports light-colored shingles reduce annual cooling costs by 10 percent to 20 percent in hot climates. Does this Spark an idea?

Read more: Light Shingles Vs. Dark Shingles | eHow.com http://www.ehow.com/about_6756345_light-shingles-vs_-dark-shingles.html#ixzz2BixuJOp9


http://thinkprogress.org/climate/2012/05/30/492153/how-painting-roofs-white-can-help-turn-off-the-world-for-a-year/?mobile=nc

How Painting Roofs White Can Help ‘Turn Off The World For A Year’

I’m drawn to “boring” ways to change energy use: things like daylighting, reducing packaging, and making company supply-chains more efficient. Without these methods to help reduce our energy demand, the “exciting” solutions like renewable energy are less valuable.

And what could be more boring than painting a roof white? Turns out, it’s also an important solution for reducing energy use and lowering carbon dioxide emissions.

A NASA survey of New York City’s rooftops last July showed that dark, heat-absorbing rooftops were up to 42 degrees F hotter than white rooftops. And that difference in heat can make a big difference in on-site energy use; painting a roof white can reduce air conditioning demand as much as 20 percent.

7 replies, 1123 views

Reply to this thread

Back to top Alert abuse

Always highlight: 10 newest replies | Replies posted after I mark a forum
Replies to this discussion thread
Arrow 7 replies Author Time Post
Reply White shingles, white rooftops, less fossil fuels, less climate impact. (Original post)
2on2u Nov 2012 OP
SubgeniusHasSlack Nov 2012 #1
jmowreader Nov 2012 #2
eShirl Nov 2012 #3
2on2u Nov 2012 #4
XemaSab Nov 2012 #5
2on2u Nov 2012 #6
XemaSab Nov 2012 #7

Response to 2on2u (Original post)

Fri Nov 9, 2012, 06:43 AM

1. Simple and effective.

 

No reason not to do this.

Reply to this post

Back to top Alert abuse Link here Permalink


Response to 2on2u (Original post)

Fri Nov 9, 2012, 06:51 AM

2. There are chemicals that make dark roofs more efficient

BASF makes a black pigment that reflects heat well, and the army has had "solar heat reflective" paints that make green reflect like white.

I wonder what the performance of sand-colored roofing is like compared to white and black? White performs well but it's ugly. I sold roofing for many years. We got four skids of white shingles when we went to GAF roofing. When I left five years later we had those same four skids. No one wanted them. OTOH we sold so much black I had the SKU (929-291) memorized. Sand seems like a good compromise between performance and curb appeal.

Reply to this post

Back to top Alert abuse Link here Permalink


Response to 2on2u (Original post)

Fri Nov 9, 2012, 06:55 AM

3. so how much heating cost is saved in winter by a dark roof?

Reply to this post

Back to top Alert abuse Link here Permalink


Response to eShirl (Reply #3)

Fri Nov 9, 2012, 06:59 AM

4. You would have to have paint that can change temp with color, I am pretty sure they can

 

figure that out.

Reply to this post

Back to top Alert abuse Link here Permalink


Response to eShirl (Reply #3)

Fri Nov 9, 2012, 07:02 AM

5. That was my question

Would it make sense to repaint the roof twice a year?

And if a house is in an area where it's hot in the summer and snowy in the winter, would a white roof help retain snow and thereby keep the house warmer?

Reply to this post

Back to top Alert abuse Link here Permalink


Response to eShirl (Reply #3)

Fri Nov 9, 2012, 07:28 AM

6. Let me think about that a bit more, if you save 20 percent in the summer... depending on the

 

temp swings..... you should lose 20 percent in the winter, unless of course your roof is covered with snow much of the time, then you have an insulation barrier that should be a bit warmer than the surrounding air..... I'm gonna have to bow out on that, don't know enough about it to say.

Reply to this post

Back to top Alert abuse Link here Permalink


Response to 2on2u (Reply #6)

Fri Nov 9, 2012, 07:47 AM

7. I don't think the math is that simple

Photoperiod and the angle of the sun would be two factors that would make a big difference in the amount of heat entering through the roof during different seasons. It also seems like factors other than the type of roof, such as types of windows, aspect, surrounding vegetation, surface/volume ratio, and construction would come into play.

But yeah, that's just me trying to think about it and not from any kind of knowledge base.

Reply to this post

Back to top Alert abuse Link here Permalink

Reply to this thread