Measurements of the thermal conductivity of refrigerants in the vapor phase

Measurements of the thermal conductivity of refrigerants R124, R125, and R I34a in the vapor phase are preseInted. The measurements, performed in a newly developed transient hot-wire instrument, cover a temperature range from 273 to 333 K and a pressure range from about atmospheric up to below the saturation pressure. A finite-elements program developed allowed the reexamination of the major corrections employed in the analysis of the results. The uncertainty of the reported values is estimated to be better than ___ 1%. Comparisons with measuremel~tS of other investigators along the saturation line show a lack of reliable thermal conductivity data in the vapor phase for these compounds.