AAWSAP DIRD, Aerospace Applications of Programmable Matter, December 2009

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Denver Five-Year Cumulative Savings
(holding energy prices constant}
-
RavenWindow+ Low-E
$3,000.00
-
Pilkington K-Glass
$2,500.00
--O!dcastle Sunglass
$2,000.00
$1,500.00
--Viracon VRE238
$1,000.00
-
AFG Comfort TiR
$500.00
,
----99% Transmissive Low­
$­
E
0
12
24
36
48
60
Months Installed
------- 99% Reflective Low-E
Figure 6. RavenWindow Smart Window Film Performance vs. Leading I ncumbent Window Filters.
Assuming a retail cost of $25 per square foot, for large buildings across multiple climate
zones, the payback period is 5-10 years. Even faster return on investment is possible if
the retail cost can be reduced, which seems likely given the relative simplicity of the
technology. The payback period does not include capital cost reduction on HVAC
systems, reduction in the cost of window coverings, and the tax and building permit
savings associated with Leadership in Energy Efficient Design (LEED) certification.
Thermal Management of Spacecraft
The three laws of thermodynamics, in their simplest form, are (1) you cannot win, (2)
you cannot break even, and (3) you cannot quit the game. Energy is never free, and
nanostructured dynamic materials are of course subject to the same laws as natural
materials. However, while energy can neither be created nor be destroyed, it can be
moved around, changed in form, and also stored. Thus, for thermal management of
spacecraft, dynamic materials have much more to offer than simply regulating solar
heat gain.
One example is active heat transport. A Peltier junction is a solid-state heat pump
made from two dissimilar semiconductors. When a current is passed through the
junction, one face grows hot while the other grows cold.
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