AHRI 421 SI
Performance Rating of Forced-circulation Free-delivery Unit Coolers for Refrigeration
|Publication Date:||1 January 2016|
This standard applies to factory-made, Forced-circulation, Free-delivery Unit Coolers, as defined in Section 3, operating with a Volatile Refrigerant fed by either direct expansion or liquid overfeed at wet and/or dry conditions.
This standard does not apply to:
Air-conditioning units used primarily for comfort cooling for which testing methods are given in other standards.
Unit Coolers operating at latent load conditions with Refrigerant Saturation Temperature < 0.0 ºC to prevent frost.
Unit Coolers installed in or connected to ductwork.
Unit Coolers using zeotropic refrigerants with Glides greater than 1.0 ºC.
Field testing of Unit Coolers.
The purpose of this standard is to establish for Forced-circulation Free-delivery Unit Coolers for Refrigeration: definitions; test requirements; rating requirements; minimum data requirements for Published Ratings; marking and nameplate data; and conformance conditions.
This standard is intended for the guidance of the industry, including manufacturers, engineers, installers, contractors, and users.
Review and Amendment.
This standard is subject to review and amendment as technology advances.