Question-and-Answer Resource for the Building Energy Modeling Community
Get s tarted with the Help page

# Revision history [back]

### wall insulation in IDF file

Following is the wall insulation in IDF file:

!- wall insulation and framing material: R21

Material, wall_consol_layer, !- Name Rough, !- Roughness 0.1397, !- Thickness {m} 0.05966275, !- Conductivity {W/m-K} 120.801, !- Density {kg/m3} 1036.25775; !- Specific Heat {J/kg-K}

But the calculation result is not equal to R21. (0.1397m)/(0.05966275W/m-K)=2.341494484m2-K/w = R13 Why?

 2 None Julien Marrec 26438 ●36 ●69 http://www.effibem.com/

### wall insulation in IDF file

Following is the wall insulation in IDF file:

!- wall insulation and framing material: R21R21
Material,
wall_consol_layer,       !- Name
Rough,                   !- Roughness
0.1397,                  !- Thickness {m}
0.05966275,              !- Conductivity {W/m-K}
120.801,                 !- Density {kg/m3}
1036.25775;              !- Specific Heat {J/kg-K}{J/kg-K}


But the calculation result is not equal to R21. (0.1397m)/(0.05966275W/m-K)=2.341494484m2-K/w R21.

(0.1397m) / (0.05966275W/m-K) = R13 2.34 m2-K/w = R13.

Why?

 3 retagged Aaron Boranian 12575 ●49 ●20 http://bigladdersoftware.com/

### wall insulation in IDF file

Following is the wall insulation in IDF file:

!- wall insulation and framing material: R21

Material,
wall_consol_layer,       !- Name
Rough,                   !- Roughness
0.1397,                  !- Thickness {m}
0.05966275,              !- Conductivity {W/m-K}
120.801,                 !- Density {kg/m3}
1036.25775;              !- Specific Heat {J/kg-K}


But the calculation result is not equal to R21.

(0.1397m) / (0.05966275W/m-K) = 2.34 m2-K/w = R13.

Why?

 4 retagged Aaron Boranian 12575 ●49 ●20 http://bigladdersoftware.com/

### wall insulation in IDF file

Following is the wall insulation in IDF file:

!- wall insulation and framing material: R21

Material,
wall_consol_layer,       !- Name
Rough,                   !- Roughness
0.1397,                  !- Thickness {m}
0.05966275,              !- Conductivity {W/m-K}
120.801,                 !- Density {kg/m3}
1036.25775;              !- Specific Heat {J/kg-K}


But the calculation result is not equal to R21.

(0.1397m) / (0.05966275W/m-K) = 2.34 m2-K/w = R13.

Why?