The DST method can be applied for solar domestic hot water systems with
and without auxiliary heating. It is therefore the most relevant test method for ‘typical’ factory-made solar heating systems used in northern and central Europe. The aim of the DST test is to determine a set of parameters, giving a detailed description of the thermal system behaviour in combination with a numerical system model. These parameters are determined by means of parameter identification using measurements recorded during operation of the system at a test facility. Annual performance of the system can be predicted by using the numerical system model and the parameters determined from the system test.
The DST test method is standardized in ISO/DIS 9459—5 (a formal ISO/CEN joint procedure, aiming at publishing the DST test method as an official standard, is underway) and has been developed mainly within the German research project VELS I (VELS:Verfahren zur Ermittlung der Leistungsfahigkeit von Solaranlagen). Its comprehensive validation was principally carried out within the work of the International Energy Agency (Solar Heating and Cooling Programmes Task 14) and in a project supported by the EU (Bridging the Gap). It was shown that the DST method is able to give reproducible results for a wide range of various types of solar domestic hot water systems and different climate conditions and locations. Furthermore, it was shown that results determined with the CSTG and DST methods for solar domestic hot water systems without an integrated auxiliary heater are comparable.