1.1 This part of ISO 16358 specifies the testing and calculating methods for seasonal performance factor of equipment covered by ISO 5151, ISO 13253 and ISO 15042. For the purposes of this part of ISO 16358, it is assumed that any make-up heating will be provided by electric heaters running concurrently with the heat pump. 1.2 This part of ISO 16358 also specifies the seasonal performance test conditions and the corresponding test procedures for determining the seasonal performance factor of equipment, as specified in 1.1, under mandatory test conditions and is intended for use only in marking, comparison, and certification purposes. 1.3 This part of ISO 16358 does not apply to the testing and rating of: a) water-source heat pumps or water-cooled air conditioners; b) portable units having a condenser exhaust duct; c) individual assemblies not constituting a complete refrigeration system; or d) equipment using the absorption refrigeration cycle.