There are 2 possible configurations for a Dualsun solar pool-heating system: 

In this setup, the pool water flows directly through the panels and no glycol mix used.  Therefore, during the winter months, the panels must be drained to avoid any risk of freezing.  In this configuration, only the Dualsun SPRING panel in portrait-mode is compatible. Advantages of this configuration:

• Better energetic efficiency efficient energetically

• Cost

• simple to install

• No glycol

• SPRING3 in portrait mode only

The closed-circuit configuration integrates a heat exchanger to heat the pool.  This configuration is adapted for combining domestic hot water heating and pool heating using the  same solar installation. 

The advantages of this solution are : 

• Coupling with domestic heat water heating, you optimize the quantity of heat produced by your panel

• Easy integration to an existing swiming pool

• No need for draining in winter
  

• SPRING4

• SPRING3
  

To go further : FAQ section pool heating