Stanford engineers
have invented a material designed to help cool buildings.
The material
reflects incoming sunlight, and it sends heat from inside the structure
directly into
space as infrared radiation (represented by reddish rays).
(November 26, 2014) A new ultrathin multilayered material can
cool buildings without air conditioning by radiating warmth from inside the
buildings into space while also reflecting sunlight to reduce incoming heat.
Stanford engineers have invented
a revolutionary coating material that can help cool buildings, even on sunny
days, by radiating heat away from the buildings and sending it directly into
space.
A team led by electrical
engineering Professor Shanhui Fan and research associate Aaswath Raman reported
this energy-saving breakthrough in the journal Nature.
The heart of the invention is an
ultrathin, multilayered material that deals with light, both invisible and
visible, in a new way.
Invisible light in the form of
infrared radiation is one of the ways that all objects and living things throw
off heat. When we stand in front of a closed oven without touching it, the heat
we feel is infrared light. This invisible, heat-bearing light is what the
Stanford invention shunts away from buildings and sends into space.
Of course, sunshine also warms
buildings. The new material, in addition dealing with infrared light, is also a
stunningly efficient mirror that reflects virtually all of the incoming
sunlight that strikes it.