I know you had a 30-year warranty, but—after 15 years—those shingles simply must be replaced. Anyone can call a roofer, but why not take a shot at making your own shingles? But first you need a formulation—the recipe—and I’ve got just the one for you. And while we’re at it, let’s compare shingle manufacturing to metal roofing manufacturing.
Announcer: There is nothing wrong with your television set. Do not attempt to adjust the picture. We are controlling transmission. We will control the horizontal. We will control the vertical. We can change the focus to a soft blur or sharpen it to crystal clarity. For the next hour, sit quietly, and we will control all that you see and hear. We repeat: there is nothing wrong with your television set. You are about to participate in a great adventure. Continue reading
In the arena of university R&D, one often thinks, who cares? I certainly do. But in this and the next post, you will read about some fascinating work coming out of Stanford University. As a self-professed cynic, I would never mention “the next great thing” if I did not see some very real potential. There is, of course, a big valley between R&D and commercial reality, but from what I have heard and read … well, you be the judge.
One of these ideas that could fall into the “too good to be true” category is radiative cooling. Before you fear that I’ve taken leave of my senses, yes, I do understand that all objects radiate energy and will cool as a result. All cool-roofing codes contain an emittance requirement for this reason. Objects (such as painted metal roofing) with a high thermal emittance (>75%; a perfect emitter would be 100%) cool down faster than low-emittance materials such as shiny metal. When the sun sets, you want the roof to radiate as much heat as possible to the atmosphere as fast as possible. Of course, when the sun is beating down on the roof, you also want the roof to reflect as much heat as possible in the form of infrared radiation (IR), keeping the roof as cool as possible. That’s why both parameters—reflectance and emittance—are important in the cool-roofing arena. Continue reading