本文将AHRAE标准项目委员会（SSPC）90.1早期开发并采用的基于相关性的方法应用于计算单层和双层玻璃纤维金属建筑（MB）隔热组件的总传热系数（U系数），扩展到以填充空间（空腔）的方式使用隔热的组件在两个连续的结构构件（檩条或围梁）之间。这些组件可能涉及单个或多个绝缘层，空腔可能被填充到不同程度。本文介绍了一种计算MB绝缘组件各区域热阻的通用技术方法，即结构单元以外、下方和上方的区域。这些分区热阻组合为单个、整体或系统热阻R insul- 系统采用串联和并联组合，同时允许热短路或优先热流通过金属结构元件和环境空气的热阻。该相关性被称为Choudharycorrelation，使用以下方程式计算NSUL系统的装配U系数。1.U=0.8672Rinsul-sys+1.132在上述方程式中，U的单位为Btu/ft2·h·F，R的单位为inft2·h·F/Btu（1 Btu/ft2·h·F=5.6782W/m2·K，1 ft2·h·F/Btu=0.17611 m2·K/W）。13Mb隔热组件的U系数，包括使用相关性计算的各种玻璃纤维隔热材料，与使用三维数值方法计算的值的一致性为93.5%至100%。此外，对于有测量U系数的四个组件，基于相关性的结果与测量值的一致性为91%到100%。 Choudhary相关性严格适用于两个连续结构单元之间5英尺（1.52米）的固定间距。引文:2016年冬季会议，佛罗里达州奥兰多，2016年交易，第122卷第。1.

The paper extends the application of a correlation-basedapproach developed earlier and adopted by the AHRAE StandingStandard Project Committee (SSPC) 90.1 for calculatingthe overall heat transfer coefficients (the U-factors) of singleand double layered fiberglass metal building (MB) insulationassemblies to assemblies where insulation is used in a mannerdesigned to fill up the space (the cavity) between the twoconsecutive structural elements (purlins or girts). Theseassemblies may involve either single or multiple insulationlayers, and the cavity may be filled to various extents. Thepaper describes a general technical approach to calculate thethermal resistances of various regions of an MB insulationassembly, namely regions beyond, underneath, and above thestructural units. These zonal thermal resistances are combinedinto a single, overall or system thermal resistance, R insul-sysusing series and parallel combinations while also allowing forthe thermal short circuiting or preferential heat flow throughthe metallic structural elements and the thermal resistances ofthe ambient air. The correlation, referred to as the Choudharycorrelation, calculates the assembly U-factor toRinsul-sys usingthe following equation.1?U = 0.8672Rinsul-sys + 1.132In the above equation U is in Btu/ft2·h·°F and R is inft2·h·°F/Btu (1 Btu/ft2·h·°F=5.6782W/m2·K and 1 ft2·h·°F/Btu= 0.17611 m2·K/W).The U-factors for 13MBinsulation assemblies, consistingof a wide range of fiberglass insulations calculated using thecorrelation, are found to be in 93.5% to 100% agreement withthe values calculated using three-dimensional numericalapproaches. In addition, for four assemblies for whichmeasured U-factors were available, the correlation basedresults were in 91% to 100% agreement with the measuredvalues. The Choudhary correlation is strictly applicable to afixed spacing of 5 ft (1.52 m) between two consecutive structuralelements.