Professors Claim Passive Cooling Breakthrough Via Plastic Film (sciencemag.org)

What if you could cool buildings without using electricity? charlesj68 brings word of "the development of a plastic film by two professors at the University of Colorado in Boulder that provides a passive cooling effect." The film contains embedded glass beads that absorb and emit infrared in a wavelength that is not blocked by the atmosphere. Combining this with half-silvering to keep the sun from being the source of infrared absorption on the part of the beads, and you have a way of pumping heat at a claimed rate of 93 watts per square meter.
The film is cheap to produce -- about 50 cents per square meter -- and could create indoor temperatures of 68 degrees when it's 98.6 outside. "All the work is done by the huge temperature difference, about 290C, between the surface of the Earth and that of outer space," reports The Economist.

Comments

Re:You amerikan infidel

[swimboy]

You non-RTFA infidel! The article states the temperatures as 20C and 37C respectively.

Re:Too good to be true.

[DamonHD]

It's called physics, even if you don't find it interesting.

1) Letting visible light through in principle lets the PV work while keeping it cool. The increase in output with lower temperatures is quite significant, thus the presence on the market of combined PV/Thermal panels for example. (And absorbing more of the visible light and removing the energy as electricity rather than letting it turn into heat would be good too, natch, and that one is being worked on.)

2) Outer space is at ~3K/-270C: having that as your cold sink *day and night* is really quite significant. What I cannot work out is if clouds are transparent at the same wavelengths, eg if this could be used to make the cold end of a Seebeck device even under cloudy skies: that would allow a small amount of power generation day and night also, if so.

This looks plausible to me and and an astonishingly good thing if it works even a 1/10th as well as the researchers hope.

Sometimes the science is good before the marketing people get to it.

Rgds

Damon