I want to verify TABLE 6.8.2B Minimum Duct Insulation considering the thermal resistance of a cylindrical wall, which is determined according to the logarithmic equation you can see at the end of this wikipedia page:
https://en.wikipedia.org/wiki/Thermal_resistance#Radial_Systems
According to that equation thermal resistance is in K/W, but TABLE 6.8.2B provides values in m2*K/W.
Shall I multiply for the exteral area of the pipe, including the insulation, in order to have a vaule that is comparable with the values provided by TABLE 6.8.2B?
Best Regards
Tyler Thumma
7GroupLEEDuser Expert
67 thumbs up
June 3, 2021 - 11:06 am
I believe you should multiply by the cross-sectional area of the insulation rather than the external area of the pipe.
However, I'm not sure why this is something you would need to calculate in this way. Typically the pipe insulation manufactuerer would be able to provide the R-value to verify compliance with Table 6.8.1B.
Francesco Passerini
engineer90 thumbs up
June 10, 2021 - 9:06 am
Probably the R-value to verify compliance with Table 6.8.1B is provided by the manufacturer in the US but the project I'm considering is in Europe.