What is the equipment for a solar water heating system ?


You will find below the diagram for an Individual Solar Water Heater (ISWH), which produces Domestic Hot Water (DHW), with our DualSun SPRING hybrid solar panels.  


We can group the ISWH’s components as following : 

  1. DualSun panels (panels + hydraulic connections + pipes + mounting rails + inverter)

  2. Solar station (hydraulic transfer system + solar controller) 

  3. Solar tank (water storage tank + extra water heating system)


1- Solar panels and their hydraulic connections



DualSun hybrid solar panels and their hydraulic connections include :  

  • DualSun SPRING panels*

  • The panel temperature sensor PT1000 FKP4** (solar panels → solar station), provided and included in the essential kit* (see below)

  • The hydraulic connection between panels: 

    •  The DualQuick Fit* interpanels connectors (built on an EPDM hose), allows the hydraulic connection between the panels.

    • SPRING inlet / outlet fittings kit*. This is used to connect the EPDM hose to the system’s pipework.



Regarding the pipe material between the DualQuick Fit hose and the solar station, you can use either option:

  • Multilayered tube (make sure it can withstand temperatures up to 90°C/194°F)**

  • Corrugated stainless steel hose**

And, like any photovoltaic project : 


2- Solar station**

The solar station is usually located near the water tank. It maintains and drives the fluid flow between the panels and the solar tank.   It includes :

  • A hydraulic transfer system



It makes the fluid flow through the pipes from the solar panels to the solar tank, and it is made up of essential components for the hydraulic commissioning including:

  1. 3 bar safety valve pre-mounted

  2. Pressure gauge

  3. Drain valve

  4. Valve with integrated check valve

  5. Filling valve

  6. Pump Wilo (circulator)

  7. Flow meter

  8. Valve with integrated check valve

  9. Air vent 


  • A solar controller SLL (or CS/Plus)

The solar controller controls the activation (and deactivation) of the pump according to the temperature difference between the panels (Glycol based water) and the bottom of the domestic storage water tank.


3- Solar tank***

  The solar tank consists of a water storage tank with a solar heat exchanger, located at the bottom of the tank, that enables the storage of domestic hot water***. It includes a thermowell at the bottom, where the PT1000/FRP6 temperature sensor is inserted.   This storage tank includes usually an extra water heating system*** (electric resistance, heat pump etc.), or can be supplemented with a second domestic hot water storage tank, which will be preheated by the solar tank.   

Please make sure that the solar tank you ar using is compatible with our system : 

To go further :  What are the hot water solar tanks compatible with DualSun SPRING panels?

4- Heat transfer fluid

Finally, a mixture of water and glycol*** (solar antifreeze that prevents the liquid from freezing in low temperature) must be used. This is the solar fluid that will flow through the panels, the pipes and the solar tank heat exchanger (see below a photo of a premixed container).  



The hydraulic commissioning corresponds to the insertion of this fluid into the system (panels, pipes). This fluid transfers the heat collected from the solar panels to the solar tank through its heat exchanger (located at the bottom of the tank) to produce domestic hot water.   

The hydraulic commissioning/insertion must be done with a filling and flushing station**** (or commissioning pump). Below is an example of a filling station/pump.



Every DualSun installation comes with a DualSun essential kit consisting of : 


Finally, we can divide this equipment into 4 categories, whether it is made and/or commercialized by DualSun:    


Required and provided by DualSun only* 

Required and potentially provided by DualSun**

Required and not provided by DualSun***

Optional and potentially provided by DualSun****


  • Filling station



For more information: