This list can be used to compare different materials used in construction and particularly windows and doors. The ratings given for aluminum as compared to vinyl or wood are significant. It is accurate to say that vinyl as a window material is 1000 times more energy efficient than aluminum, and that pine is 1700 times more energy efficient. Now to be realistic, most of the surface in windows is glass, where vinyl is a mere 4 times more energy efficient than single pane glass. Make that glass thermal pane with a non-conductive spacer system, and add in argon (or krypton) gas, and you have a superior window from a efficiency standpoint. The material that conducts the quickest--copper, which is why it is used for electrical wiring. Also, it's good to know where wool blankets rank in the mix.
Thermal conductivity of some common materials and products are indicated in the table below.
* 1 W/(m.K) = 1 W/(m.oC) = 0.85984 kcal/(hr.m.oC) = 0.5779 Btu/(ft.hr.oF)
* Conduction will take place if there exist a temperature gradient in a solid (or stationary fluid) medium.
* Energy is transferred from more energetic to less energetic molecules when neighboring molecules collide. Conductive heat flow occurs in the direction of the decreasing temperature since higher temperatures are associated with higher molecular energy. Fourier's Law express conductive heat transfer as q = k A dT / s
* A = heat transfer area (m2, ft2)
* k = thermal conductivity of the material (W/m.K or W/m oC, Btu/(hr oF ft2/ft))
* dT = temperature difference across the material (K or oC, oF)
* s = material thickness (m, ft)
Thermal conductivity of some common materials and products are indicated in the table below.
1 W/(m.K) = 1 W/(m.oC) = 0.85984 kcal/(hr.m.oC) = 0.5779 Btu/(ft.hr.oF)
Conduction will take place if there exist a temperature gradient in a solid (or stationary fluid) medium.
Energy is transferred from more energetic to less energetic molecules when neighboring molecules collide. Conductive heat flow occurs in the direction of the decreasing temperature since higher temperatures are associated with higher molecular energy. Fourier's Law express conductive heat transfer as
q = k A dT / s (1)
where
A = heat transfer area (m2, ft2)
k = thermal conductivity of the material (W/m.K or W/m oC, Btu/(hr oF ft2/ft))
dT = temperature difference across the material (K or oC, oF)
s = material thickness (m, ft)
Krypton .0088
Argon .016
Acrylic .02
Oxygen .024
Cotton .029
Polystyrene .03
Polyurethane foam .03
Styrafoam .033
Wool blankets .04
Fiberglass .04
Fiber insulation board .048
Plywood .13
Pine .147
Oak .17
Gypsum .17
Vinyl .25
Water .58
Concrete 1.0 - 1.8
Glass (single pane) 1.05
Slate 2.01
Marble 2.08 - 2.94
Ice 2.18
Rock 2 – 7
Stainless steel 16
Lead 35
Carbon steel 54
Tin 67
Platinum 70
Nickel 91
Brass 109
Zinc 116
Aluminum 250
Gold 310
Copper 400
Taken from http://www.engineeringtoolbox.com/conductive-heat-transfer-d_428.html
.jpg)
