Farnsworth Homework
Farnsworth House and Climate Data
Dimensions:
Length = 77.0 ft
Width = 29.0 ft
Height = 9.5 ft
Aroof = Surface Area (ft2) of the 77ft x 29ft roof
Afacade = Surface Area (ft2) of the roof and facade (all four walls).
Ai = Total surface area of the roof and facade = Aroof + Afacade
Thermodynamic Properties:
Sigma = .17 x 10-8 BTU/(hr)(ft2)(oR4)
Eroof = Emittance of roof = .80
Efacade = Emittance of facade (= absorptance) = .05
Tsky = Temperature of the surroundings (in this case, the sky) = Toutside - 7oF
Toutside = Exterior temperature in oR (oR = oF + 451)
Tinside = Temperature of air inside the house in oR (oR = oF + 451)
Rfacade = Thermal resistance rate of the facade = .025 oF(ft2)(hr)/BTU
Rroof = Thermal resistance rate of the roof 11.0 oF(ft2)(hr)/BTU
Ri = Total thermal resistance rate = Rfacade + Rroof