ISO 9459-4:2013 PDF Download

A procedure for assessing the annual energy performance of solar water heaters is described in ISO 9459-4:2013. The performance of the system's annual load cycle task under certain weather and load conditions is determined by combining test findings for component performance with a mathematical model. It applies to integral collector storage water heaters as well as solar water heaters with integral backup or preheating into a traditional storage or instantaneous water heater.

Requirements for product design or operation are absent from the standard. Instead, it concentrates on defining the system requirements in order to rate the annual performance of home water heaters. The ISO 9459-4:2013 standard establishes a uniform technique for assessing system performance, ensuring consistency and comparability across various solar water heating systems.