There exists 2 configurations for a DualSun solar pool-heating system:
1) Drainback version (open-circuit): the pool water flows directly through the panels and no glycol mix used. In effect, 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:
- more efficient energetically,
- simpler to install,
- none of the constraints associated with glycol.
2) Pressurized version (closed-circuit): 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. This system is compatible with DualSun Wave and DualSun Spring panels in portrait or landscape mode, since a glycol-mix is used for the heat-transfer fluid that flows through the panels and thus the panels do not need to be drained in the winter. Note 1: it is possible to have a 6-panel ECH2O Sun installation in the closed-circuit configuration if you would like to use the DualSun panels for both hot water and pool heating. However, this requires additional material:
- DualSun SLT solar controller station instead of the DualSun CS2 solar station
- A stainless steel heat exchanger
- A 3-way valve
Note 2: you should always first use a pool cover if pool heating is desired, whether it be a solar heating system or other.