1. SolTherm - CEN EPBD standards based simulation model -
Gerard van Amerongen
SCF: 6C14.1 – Other model
October 2017

2. Introduction Soltherm software: combi of both CEN EPBD standards
EN , M3
(hourly)
EN (hourly)
Soltherm software: combi of both CEN EPBD standards
Open source simulation model
Input parameters (major part) from Solar Keymark datasheets
Collector, tank and controller
Less detailed than scientific model, more detailed than Fchart method
Fchart: EN , M2 (monthly)
SCF project: develop software and validate

3. The model Commonly applied solar thermal system layout
Water & space heating
Backup heating, but not (yet) the backup heater

4. The SolTherm software
The MsWindows application is available for evaluation purposes only
You can develop your own user interface and connect to the model (.DLL).
All Microsoft (alike) development surroundings and more
C++, VB, Excel…. PS
Fully functional for water heaters
Combi systems need an update for the definition of backup heater control
The Wurzburg, Athens and Stockholm climates are not yet according to DST testing

5. Inputs for the model: Additional inputs:
Data from collector Solar Keymark datasheet
Asolmod ηo a1 a2
IAM
mcol
Data from tank Solar Keymark datasheet
Height
Vsto
Hsto
Hsto;exch
Connections to tank
Data from controller Solar Keymark datasheet
Thermostat settings
Additional inputs:
Backup heater(s): Output power, control settings
Pump and control: power consumption
Collector loop: number of collectors and heat loss rate
Location of tank and collector loop

6. Validation
8 systems, different load sequences, validated against TRNSYS (ITW)
2 types of water heaters and 3 types of combi heaters
Solar water heaters: according to ErP references
Combi heaters: ITW supplied climate and load sequences
Validated for annual heat contribution backup heater (=Qbu)
Relative deviation (Qbu,SolTherm – Qbu,TRNSYS)/Qload
Water heaters: Qload = load sequence for water heating
Combi heaters: Qload = Total of water and space heating load

7. Validation results
SolTherm (on average) higher solar thermal performance
SolTherm accuracy within (assumed) accuracy TRNSYS
Good correspondence for all validated system types
Blue boxes group results of the same solar thermal system

8. Validation results - DST test result -
Based on full set of Solar Keymark datasheets
(collector, tank, controller, systems)
Preheater solar water heater
Climate: Davos, heat demand 110 l/d -> 400 l/d
One brand, different members of product family
PS:
Results for other climates will follow. Due to issues in the climate files not yet available

9. Options for application
Member states energy performance regulations
Much better than the monthly method (=‘Fchart’)
Potential for systems with solar contribution
Hourly methods are included in EPBD standards for all types of heating devices
EN Custom built solar thermal systems
Include SolTherm as a requirement for a strong CEN standard reference
EN Factory made solar water heaters
Future use an alternative simulation model (instead of P-model)
Define parameter set and link to parameter identification software
Existing datasets could be used again
Solar Keymark
Strong reference to CEN standards
ErP regulations
Future application of the method

10. Conclusions EN 15316-4-3 hourly methods: base for dedicated software
Methods needs further development (discussed in TC228 WG4)
SolTherm seems accurate enough for EPBD purposes and Solar Keymark certification
Based on limited validation trials
No validation for thermo syphon systems yet
Further validation needed
Should be applicable in DST testing (EN )
Further work needed
First validation results: good

11. Proposals Try the software and experience its functionality
and share your experiences in the SolTherm forum
Establishment of software management group
Management of: ScenoCalc, SolTherm, foreseen SOLCAL tool, …
Further validations, maintenance, new tools, …
Allow for SolTherm in EN
First phase: to complete the datasheets
Next phases: following proposals ‘broadening the scope …’ SCF project
Feasibility study: SolTherm in DST testing
Select parameters and identification tool, validation existing datasets

12. For your attention