scope:

This document sets out a method for evaluating the annual energy performance of water heaters using a combination of test results for component performance and mathematical models to determine the standardized annual supplementary energy use.

This document may be used for both domestic and commercial systems, including recirculated hot water systems. For commercial applications, the systems modelled may deliver heat through fluids other than water.

The procedures may be used for solar and heat pump water heaters (HPWHs) with or without integral gas or electric boosting and may be coupled to conventional storage or instantaneous water heater(s) when used as solar pre-heater(s). Solar energy sources considered are -

(a) solar irradiance which is used in solar thermal collector applications;

(b) photovoltaic array applications; and

(c) air-sourced heat that is used for heat pump applications.

The calculations in this document also cover the displaced purchased energy relative to reference water heaters.

NOTE Solar and solar-boosted HPWH types not covered in this document may be tested under AS 2984 to obtain an annual performance assessment.

This document does not include product design or operation requirements, however for the purpose of rating it does specify minimum savings and water temperature delivery requirements used to select simulated thermal load size.