"It was possible to adapt to cold environments, for example, by either increasing metabolic heat production, decreasing
thermal conductance, or both--the interaction between the two is what really mattered.
Chen, "Enhancement of thermoelectric performance in beta-graphyne nanoribbons by suppressing phononic
thermal conductance," Carbon, vol.
Thermal H/W Parameter Value SSM [9] Solar absorptivity 0.1 IR emissivity 0.9 Louver [9] Solar absorptivity 0.17 Effective IR emissivity 0.7 (open)/0.09 (close) Blade open/close set 0 point ([degrees]C) Heat switch
Thermal conductance 6.58 (open)/640.66 (close) [9] (W/[m.sup.2]/K) 0 Switch open/close set point ([degrees]C) SSM Shutter Radiator Thermo-optical property Table 4 (shutter) Shutter panel open/close 0 set point ([degrees]C) Table 4: Thermo-optical properties of thermal coatings used to shutter.
Remarkably, an exact analytical solution can be constructed using an integral transform method [16] which provides a complete description of the crossover of the
thermal conductance moments as a function of the system's length, covering all transport regimes: ballistic, metallic, and insulating.
Properties REF VG1 VG2 Thickness of layers (mm) 4 4-0.2-4 4-0.2-4 Emissivity of surfaces (-) 0.85/ 0.85/0.85/ 0.85/0.85/ 0.85 0.85/0.85 0.2/0.85 Solar transmittance (-) 0.92 0.85 0.79
Thermal conductance at 274.39 4.68 1.62 20[degrees]C (W/[m.sup.2] x K) Table 2: Summary of the collector simulation results.
where S is the solar irradiance incident on the window, [A.sub.STPV] is the surface area of the STPV window, and SHGC and U are the solar heat gain coefficient and the
thermal conductance of the STPV window, respectively.
"Resistors" represent
thermal conductance. The circles are simplified visualizations for more complex electric circuits consisting of a parallel circuit of a current source (heat loss) and a (heat) capacity between the node and "electric ground." The size of a circle correlates with the size of the capacity, the size of an arrow correlates with the size of the current source, and the size of a resistor correlates with the size of conductance.
A 1.2-m by 2-m by 0.185-m-thick wall section had an apparent
thermal conductance of only 0.204 W [m.sup.-2] [K.sup.-1] including the structural wood frame, which is equivalent to a US R-value of 27.9 h [ft.sup.2] [degrees]F [Btu.sup.-1] (3.8 h [ft.sup.2] [degrees]F [Btu.sup.-1] [in..sup.-1] for the 7.3-in.-thick wall section).