How are Dualsun modules protected against frost?

In our pressurized systems, glycolated water is used in order to protect against freezing. The concentration of glycol determines the freezing point of the fluid:

In Dualsun pool systems, the system circulates water from the pool and the panels function with an auto-flush. Although the panels are able to drain themselves almost entirely, there may still be a small amount of water at the bottom of the exchangers.

So, how are they protected from freezing?

We carried out tests on our panels at -30°C, after filling and emptying the exchangers. There was still a small amount of water inside, but the integrity of the panels was well preserved! The space available in the channels is sufficient to allow the expansion of the water remaining there when it freezes. So maintaining your installation during the wintertime is easy.