This part of ISO 13261 specifies methods for the determination of sound power ratings of air-conditioning and air-source heat pump equipment to be used indoors. It is applicable to the sound power rating of the indoor sections of non-ducted, factory-made, residential, commercial and industrial air-conditioning and air-source heat pump equipment, which are electrically driven with mechanical compression including free-delivery heat pumps, packaged-terminal air conditioners and water-source heat pumps.