ASHRAE Standard 79 prescribes laboratory methods of testing the capacity of fan-coil units.

In the 2015 edition of the standard includes the following changes:

• Updates to the traceability for calibration of test instruments were brought in alignment with other related standards, and test instruments were updated to current models.
• References to an alternative method of airflow were added.
• New material was added to update and clarify methods for testing exposed and concealed fan coils for total sound, as well as methods to measure sound paths for discharge and radiated sound.
• An alternate method of airflow measurement was added.
• Two new annexes, Informative Annex C, "Alternate Mixing-Tube Reference Dimensions," and Informative Annex D, "Examples of Various Types of Exposed and Concealed Fan Coils" were included.
• Figures were updated to improve resolution and clarity, and new figures were added.
• Minor editorial changes were made, along with updates to normative references.