Ouside temperature, inside air condition and condensation on inside glass windows
The combination of
- outside temperature, and
- inside air condition - inside dry bulb temperature 65 oF (18.3 oC) and variable inside relative humidity, and
- moisture condensation on inside surfaces of glass windows
are indicated in the charts bellow.
Windows - Overall Heat Transfer Coefficients U
- Single glass window : U = 1.13 (Btu/ft2 oF hr) = 6 (W/m2 oC)
- Double sealed glass window : U = 0.58 (Btu/ft2 oF hr) = 3 (W/m2 oC)
Example - Condensation on Window Surface
- an indoor relative humity of 50%, and
- a window with a single glass with an U-value of aprox. 6 (W/m2 oC), 1.13 (Btu/ft2 oF hr)
- condensation on the inside of the glass will occur from outside air temperature 6oC (43oF) and below according the chart above.