This standard applies to factory-made Air-to-Air Heat Exchangers for use in Air-to-Air Energy Recovery Ventilation Equipment as defined in Section 3.

Exclusions. This standard does not apply to the rating and testing of heat exchangers joined by circulated heat transfer medium (run-around loop). A run-around loop employs liquid-containing coils connected in a closed loop and placed in each of two or more airstreams.

Purpose. The purpose of this standard is to establish for Air-to-Air Heat Exchangers intended for use in Air-to-Air Energy Recovery Ventilation Equipment: definitions; test requirements; rating requirements; minimum data requirements for Published Ratings; marking and nameplate data; and conformance conditions.