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