This solar hot water calculator shows the energy, CO2 emission and financial savings that a SOLFEX solar thermal system could yield. It also tells you which SOLFEX products would be needed for the installation.
This tool calculates the performance of a SOLFEX solar hot water system according to the Government’s Standard Assessment Procedure for Energy Rating of Dwellings (known as SAP 2009). It is only suitable for domestic properties.
There are two versions of the calculator, one for installers/merchant groups, and one for homeowners. The homeowner version asks for less information to make it simple to complete, but in doing so makes the following assumptions about the solar hot water system.
Step 3 of 4 – Hot water heating system
A ‘Cylinderstat’ (thermostat for the hot water cylinder) is fitted to the current boiler
The current system is not a low water design, meaning that the water consumption of the property will be higher than 125 litres/person/day
Step 4 of 4 – Solar thermal system
An appropriately sized direct type cylinder based on the number of bedrooms, bathrooms and additional showers
Collector models are ‘FK500P’ for flat plate and ‘CPC INOX 12/18’ for evacuated tube, including the number of panels according to cylinder size
A Solar Photovoltaic (PV) powered pump is not installed
Mounting of the collectors on-roof using roof hook fixings
Other options are available from SOLFEX e.g. different cylinder and collector types and roof mounting options. If you would like to explore these, please select the ‘Installer’ option from Step 1 of the calculator.
Other assumptions for SAP 2009 calculation
Conversion factor for kWh to litre conversion: 9.8
Conversion factors for kWh to m3 conversion: calorific value = 40.0, volume conversion factor = 1.02264
Pre-heating system: twin-coil cylinders for all calculations