BS 5918:2015

Foreword
Introduction
1 Scope
2 Normative references
3 Terms and definitions
4 General recommendations
5 Site inspections and technical pre-installation surveys
6 Provision of customer information
7 Details of key components
8 Installation
9 Commissioning and documentation
10 Maintenance
11 Performance predictions
Annexes
Annex A (normative) - Bacterial growth and safety in
        DHW systems
Annex B (informative) - Characteristics of an average UK
        household DHW usage profile
Annex C (informative) - Example primary system layouts
Annex D (informative) - Site inspection
Annex E (normative) - Minimum wall thickness for high-temperature
        EPDM-based rubber insulation
Annex F (informative) - Nominal amounts of DHW supplied
        by point-of-use appliances that are usually not available
        for solar preheating
Annex G (informative) - Example sizing of collector active area
Annex H (informative) - Worked example - Expansion vessel sizing
Annex I (informative) - Troubleshooting
Annex J (informative) - Methods for calculating loss of irradiation
         due to shading obstacles
Bibliography

Provides recommendations and guidance for the installation of common indirect solar domestic hot water (SDHW) systems for all types of building in the UK.

This British Standard gives recommendations and guidance for the installation of common indirect solar domestic hot water (SDHW) systems for all types of building in the UK. It includes recommendations and guidance for design, handling, installation, commissioning, handover, maintenance, decommissioning and fault-finding. NOTE1 SDHW is domestic hot water (DHW) that has intentionally received heat derived from solar radiation via a solar collector. The standard covers systems: in which solar radiation is converted to heat that is primarily intended for domestic hot water preparation; that contain solar collector(s) intended to transfer heat using an aqueous-based liquid medium; whose solar collectors conform to BSEN12975‑1 and BSENISO9806; which contain collectors that provide up to 20kW instantaneous peak power output measured leaving the collector, when tested in accordance with BSENISO9806 at 800W/m2 perpendicular to the collector aperture plane; NOTE2 Depending on the characteristics of the system, this typically equates to a gross collector area of up to approximately 30 m2. in which heat is primarily stored in aqueous-based liquid media; and in which the primary circuit is indirect with a heat exchanger that is internal to the solar storage vessel and which separates the primary heat transfer fluid that passes through the collector from the DHW. This British Standard does not cover: applications that are primarily intended to provide heat for applications such as space heating, cooling or swimming pools and any other than DHW preparation; solar primary system layouts that use solar storage vessels that are outside the building; solar primary system layouts with multiple collector fields; DHW systems that comprise multiple solar or multiple DHW storage vessels; or solar primary system layouts that incorporate a heat pump or other device that utilizes the Carnot cycle. NOTE3 It is assumed in the calculations in this British Standard that there is user-disinterest in the DHW settings, i.e. that default factory timer and thermostat settings are present. Extra heating required for bacterial disinfection is not assumed in these calculations. NOTE4 Where stated in the standard, the pressure is that exceeding atmospheric pressure at sea level.