ISO 13253:2017 specifies performance testing, the standard conditions and the test methods for determining the capacity and efficiency ratings of air-cooled, air-conditioners and air-to-air heat pumps.

ISO 13253:2017 is applicable to the following equipment:

- ducted air-cooled air conditioners and ducted air to air heat pumps.

ISO 13253:2017 is limited to

- residential, commercial and industrial single-package, and split-system air conditioners and heat pumps,

- factory-made, electrically driven and use mechanical compression,

- utilizing single, multiple and variable capacity components, and

- multiple split-system utilizing one or more refrigeration systems, one outdoor unit and one or more indoor units, controlled by a single thermostat/controller.

The requirements of testing and rating contained in this document are based on the use of matched assemblies.

ISO 13253:2017 is not applicable to the rating and testing of the following:

a) water-source heat pumps or water-cooled air-conditioners;

b) multi-split-system air-conditioners and air-to-air heat pumps (see ISO 15042 for testing of such equipment);

c) mobile (windowless) units having a condenser exhaust duct;

d) individual assemblies not constituting a complete refrigeration system;

e) equipment using the absorption refrigeration cycle;

f) non-ducted equipment (see ISO 5151 for testing of such equipment);

g) ducted air conditioners and/or ducted heat pumps, rated at less than 8 kW and intended to operate at external static pressures of less than 25 Pa, controlled by a single thermostat/controller (refer to ISO 5151).

ISO 13253:2017 does not cover the determination of seasonal efficiencies, which can be required in some countries because they provide a better indication of efficiency under actual operating conditions.

NOTE Throughout this document, the terms "equipment" and "systems" mean "air-conditioners" and/or "heat pumps".