BS EN 13203-3:2022

This document is applicable to solar supported gas-fired appliances producing domestic hot water. It applies to a system marketed as single unit or a fully specified system that: - has a gas heat input not exceeding 70 kW; - has a hot water storage tank capacity not exceeding 500 l; - is equipped with at least one solar collector; - is, with regard to the solar hydraulic circuit, considered as a forced circulation system (definition according to EN ISO 9488:1999). The appliances covered by this document are described in Annex E (normative). This document does not apply to thermo-siphon or integral collector storage tank systems according to definitions given by EN ISO 9488:1999. NOTE In principle, the energy consumption of thermo-siphon solar preheat systems and integral collector storage tank preheat systems can also be assessed based on this document. One appropriate procedure for that purpose is to calculate the temperature level of the domestic hot water withdrawn from the thermal solar system for the reference conditions specified in this standard by using the numerical system model and the thermal solar system performance parameters according to ISO 9459-5. Based on the temperature level of the hot water withdrawn from the store the energy consumption of the gas appliance is determined. This determination can either be done by means of calculations or by performing a test according to EN 13203 2:2022 and using instead of the cold water inlet temperature the hot water temperature withdrawn from the store. This document is not intended to assess the performance: - of the solar collector(s), which should comply with EN 12975-1:2006+A1:2010 and EN 12975-2:2006; - of thermal solar systems and components, which should comply with EN 12976-1:2021 and EN 12976-2:2019. EN 13203-1:2015 sets out in qualitative and quantitative terms the performance in delivery of domestic hot water for a selected variety of uses. It also gives a presenting the information to the user. The present document sets out a method for assessing the energy performance of a solar supported appliance. It specifies a few daily tapping cycles for each domestic hot water use, kitchen, shower, bath and a combination of these, together with corresponding test procedures including information about the available solar radiation. It enables the energy performances of different gas-fired appliances to be compared and matched to the needs of the user.