January 26, 2009
What if we painted the world white?
I recently learned a few things that I was a little shaky on.
This article talks alot about one of those things.
That is the power of WHITE – and yes I mean the color. 
For the majority of people out there we understand the ability of light colors. They reflect while dark colors absorb. And we are talking about heat for those of you just joining the conversation.
And a majority of us have heard of the concept of cool roofs. That is you paint or put some sort of white membrane on a roof and it dramitically reduces the cooling loads of a building because the temperature of the roof surface drops by 50+ degrees.
However in the above mentioned article you can read about the actual effects of a study that was conducted. This study has the audacity (a good audacity) to claim that adopting a cool roof and cool pavement strategy would change the climate drastically – drastically like 44 billion tons of CO2-
“That is more than all the countries on Earth emit in a single year. And, with global climate negotiators focused on limiting a rapid increase in emissions, installing cool roofs and pavements would offset more than 10 years of emissions growth, even without slashing industrial pollution.”
Pretty incredible! I also learned this weekend that shiny metal (which tends to reflect more than white surfaces) is not a good roofing strategy (actually it can be you just need to be aware of how to install it). This is because using a shiny metal as a “radiant barrier needs to have an air space accompanying it. Metal is a conductor and if it is placed next to another surface (i.e. you covering your roof with shiny metal) it will conduct that heat through the surface it is touching.
So what this means for you is – don’t get suckered into buying a foil faced foam board insulation to put on your roof. When you lay roofing shingles on top of it (or whatever you roof it with) you have eliminated the purpose of the radiant barrier all together. Hope this helps!
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