ASHRAE标准64规定了可通过实验室测试获得远程机械通风蒸发制冷剂冷凝器容量测定的程序、仪器和仪表，其准确度可作为商业评级的依据。2020年修订版包含了几项技术修订，以及使标准符合ASHRAE强制性语言要求的变更。参考文献也已更新。

ASHRAE Standard 64 specifies procedures, apparatus, and instrumentation by which determinations of remote mechanical draft evaporative refrigerant condenser capacity can be obtained by laboratory testing with accuracy satisfactory to be used as the basis for commercial ratings.This 2020 revision incorporates several technical revisions, as well as changes to bring the standard into compliance with ASHRAE’s mandatory language requirements. References have also been updated.