The whole R value of a construction

Hi everyone,

After creating a construction with EpConstruction, where can I find the R-value of it as a whole which the energyplus engine will use to do the simulation?
As far as I concern, there are surface coefficients of heat transfer for both the outside and inside of the envelope construction, and there are correction factors for materials when they are used as different parts of the building. Should I calculate these corrections before build the materials to a construction or the energyplus will consider one construction with differently corrected R values by the catagories wall/roof/underground and so on?

Thank you for the attention

I believe you are loking for the HB_RValueWith AirFilms component.
You don’t need to make further adjustments to the construction assembly. E+ takes care of that.

Hi Abraham,

Thank you for the reply!
So can I take it this way that if a construction for exterior wall has a R value 1(SI unit) at the output of Energyplus Construction component, the e+ will use the value 1+0.17=1.17 to run the simulation. The 0.17 comes from the HB_RValueWith AirFilms component after I compared the input and output.

You can ask and check for the html report and see the detailed material description properties.

Hi Abraham,
I found the properties in the html report but them are different from the properties in GH.
And can I ask if there’s a way to change the default values inside the e+ which can be viewed from the HB_RValueWith AirFilms component?

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Hi @AbrahamYezioro

Sorry to bother you again. I tried several more times. It seems the additional R value for air films of exterior wall/window is 0.15 if you see from the html report. But in the GH it’s 0.17.
May I ask how comes the different?

Thank you.

similar question…if i’m building a NoMass roof construction per 90.1-2013 (IEAD roof, U-0.032 for example which already includes the air films per 90.1 Appendix A)…do I input the U value as 0.032 or do I need to find the U value WITHOUT air films via the Honeybee_RValueWithAirFilms component and input THAT value as EnergyPlus is adding the airfilms in after the fact??

I have the similar question, does this have been solved in the latest version?
Thank you

Did you end up finding an answer to this? If you had to remove the air films, how would you go about that?