Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
When I look at the material inputs for Concrete Block - 8 in. - 105 lb/ft3 - Solid Grouted and use these (along with the ASHRAE-defined values for film coefficient) I get:
1/(0.17 + (8/8.4) + 0.68) = 0.5548 Btu/ft2-h-R
So the OpenStudio/EnergyPlus output makes sense to me. The difference could lie in a slight discrepancy in thermal conductivity value or (more likely) the fact that film coefficients are approximations that are subject to vary depending on what standard you are referencing or what software you are using. If you wanted to match the value that you found, I would advise adjusting the input for thermal conductivity since it seems like OpenStudio's assumed film coefficients are consistent with ASHRAE.
| | 2 | No.2 Revision |
When I look at the material inputs for Concrete Block - 8 in. - 105 lb/ft3 - Solid Grouted and use these (along with the ASHRAE-defined values for film coefficient) I get:
1/(0.17 + (8/8.4) + 0.68) = 0.5548 Btu/ft2-h-R
So the OpenStudio/EnergyPlus output makes sense to me. The difference could lie in a slight discrepancy in thermal conductivity value or (more likely) the fact that film coefficients are approximations that are subject to vary depending on what standard you are referencing or what software you are using. If you wanted to match the value that you found, I would advise adjusting the input for thermal conductivity since it seems like OpenStudio's assumed film coefficients are consistent with ASHRAE.
