I have a problem with envelope U-Factor. I modeled a Single layer polyethylene Surface and according to literature its U-Value should be around the 8 (Fig Below) but E+ calculate (U-Value =3.7).
I've changed the thickness and conduction coefficient, but they do not have remarkable effects.
I've changed the inside and outside convection coefficient at SurfaceProperty:ConvectionCoefficients according to what was discussed here (I checked Surface Face Convection Heat Transfer Coefficient at Output: Variable and it had been changed according to number I had assigned to SurfaceProperty:ConvectionCoefficients).
But the u-factor of my surface hasn't changed!!! What should I do?
