ANSI/ASHRAE Standard 41.1 prescribes methods for measuring temperature under laboratory and field conditions for use in performance testing heating, ventilating, air-conditioning, and refrigeration systems and components.

The 2024 edition of Standard 41.1 includes updated methods for determining when steady-state operation has been achieved for data recording, changes to make it easier for higher-tier standards to adopt this standard by reference, and changes to meet ASHRAE's mandatory language requirements.