scope:

This standard applies to Central Station Air-handling Units (CSAHU) as defined in Section 3.5.

Exclusions.

This standard does not apply to forced-circulation, free-delivery air-coolers for refrigeration, which are covered in ANSI/AHRI Standard 420.

This standard does not apply to unit heaters intended for free delivery of heated air or to room fan-coils as defined in ANSI/AHRI Standard 440.

This standard does not apply to units that have direct expansion coils incorporated by the manufacturer in a matched split system air-conditioner, or as otherwise defined in the product scope definition of the AHRI Unitary Small Equipment and Unitary Large Equipment Sections and covered in ANSI/AHRI Standard 210/240 or in ANSI/AHRI Standard 340/360.

This standard does not apply to unit ventilators as defined in ANSI/AHRI Standard 840.

This standard does not apply to variable refrigerant flow equipment as defined in ANSI/AHRI Standard 1230.

This standard does not apply to direct expansion (DX) dedicated outdoor air system units as defined in ANSI/AHRI Standard 920.

This standard does not apply to CSAHU's designed to only operate with internal casing pressure between -250 Pa and 250 Pa.

Purpose. The purpose of this standard is to establish for Central Station Air-handling Unit Casings: definitions; classifications; test requirements; rating requirements; minimum data requirements for Published Ratings; operating requirements; marking and nameplate data; conformance conditions.

Intent. This standard is intended for the guidance of the industry, including manufacturers, designers, installers, contractors and end users.

Thermal Performance Rating Limitations. Thermal performance ratings are intended to be used only to compare the construction of different Central Station Air-handling Units. The numerical value associated with the rating class cannot be used to predict actual application Thermal Transmittance through casing or the risk of condensation for any specific Central Station Air-handling Unit.

Review and Amendment. This standard is subject to review and amendment as technology advances.