In a world that's warming up quickly, researchers are looking for ways to cool down. Australian researchers have an additional motivation: their country is heating up faster than other places, adding an additional level of urgency to their work.
Now researchers at the University of Technology in Sydney have developed a neat new material that can keep roofs cooler than the air above them, even in direct sunlight. By preventing roofs from warming up, homeowners can expend less energy on air conditioning, and reduce the heat island effect in their city.
The material is made from layers of specialized plastics stacked on top of a layer of silver. The material reflects heat so well that it doesn't warm up, even on bright sunny days, only absorbing three percent of the sunlight that hits it. Compared to currently available roofing materials that are designed to reduce temperature (usually white roofs that reflect sunlight), the test material stayed more than 50 degrees Fahrenheit cooler. A test roof was placed on an existing rooftop in downtown Sydney and monitored for days. Even when the roof got dirty (something that happens in cities), the material still worked.
http://www.popsci.com/new-material-could-make-your-roof-cool-even-hot-summer-day
[Source]: http://newsroom.uts.edu.au/news/2015/05/super-cool-roof-solution-being-hot-city
[Paper]: http://onlinelibrary.wiley.com/doi/10.1002/advs.201500119/full
(Score: 1, Informative) by Anonymous Coward on Friday June 05 2015, @01:38PM
The popsci article didn't mention how easily it is degraded by dust, birdshit, etc.
If you look at cool roof ratings [coolroofs.org] they measure both initial performance and performance after 3 years.
Also, if you have asphalt shingles the most cost-effective way to reduce heat absorption is to paint your roof with hydrated lime. [builditsolar.com] Unless you live in a high rainfall region a single coat should last a few years.
(Score: 2) by Kromagv0 on Friday June 05 2015, @02:36PM
It sounds like it might be cheaper even if you do live in a high rainfall area. $14 and a few hours of work isn't much.
T-Shirts and bumper stickers [zazzle.com] to offend someone
(Score: 0) by Anonymous Coward on Friday June 05 2015, @06:51PM
2) Can it be a problem to pilots if all the roofs in a huge area start reflecting sunlight really well?
(Score: 0) by Anonymous Coward on Friday June 05 2015, @08:04PM
> 1) What happens if the rain water from your hydrated lime roof gets into someone's eyes?
I dunno. What happens?
> ) Can it be a problem to pilots if all the roofs in a huge area start reflecting sunlight really well?
Can it?
Just asking is all.