Thermal buffer: avoid surface evaporation of hot water with oil or other blocking product?

[Christophe]

Did you measure the melting point temperature?

Around 60-70°C it is progressive...

In your buffer, how does the hot water from the panels arrive? under or on the surface?
And where does the air come from that fills the panels every night?

Under, in both cases...but the water intake is deeper (close to the bottom) than the return (2m under water) it seems to me.

Sounds like a good question...

[dede2002]

At home, the water comes above the level, and when the pump stops, the air rises in the panels. Hence my question.

Because it creates a stir, conducive to the creation of emulsions.

[Christophe]

No, when the pump is running, I don't hear any water falling into the buffer...but when the pump starts, I hear bubbles...

It could be a problem...when the wax is solid...but the layer should quickly crack.

[dede2002]

Did you measure the melting point temperature?

Around 60-70°C it is progressive...

:

Theoretically, it shouldn't be progressive...

[dede2002]

No, when the pump is running, I don't hear any water falling into the buffer...but when the pump starts, I hear bubbles...

It could be a problem...when the wax is solid...but the layer should quickly crack.

This air cannot have been taken from the bottom of the buffer...
There must be an airing of the panels elsewhere?

[izentrop]

In real life it is decreasing (currently less 20 to 30 cm in 14 years

You have time to see it coming and no need to bother with preposterous solutions, so...

[sicetaitsimple]

Have you ever posted a curve showing the evolution of the water temperature of your buffer during a typical year?

[Christophe]

Did you measure the melting point temperature?

Around 60-70°C it is progressive...

:

Theoretically, it shouldn't be progressive...

Theoretically no but practically yes: it's not homogeneous...

Look above at the IR photos of the PIZZA-looking surface ...you will understand...

[Christophe]

No, when the pump is running, I don't hear any water falling into the buffer...but when the pump starts, I hear bubbles...

It could be a problem...when the wax is solid...but the layer should quickly crack.

This air cannot have been taken from the bottom of the buffer...
There must be an airing of the panels elsewhere?

Yes of course.

In fact there is a copper capillary that follows the main pipes of the solar panels...never knew what it was, well it may be an air pressure tap/balancing between the top solar panels and buffer air volume?

This capillary is not visible in the cellar...so I don't know exactly where it goes...

[Christophe]

In real life it is decreasing (currently less 20 to 30 cm in 14 years

You have time to see it coming and no need to bother with preposterous solutions, so...

Well yes, but no, because there you are just thinking about the lack of water... I am also thinking about the energy aspect, ie maintaining the temperature and reducing heat loss.

When I see the huge temperature differences (up to 30°C!) between the 2 trial bowls...I think this will boost calorie storage in an interesting way! (see very 1st post of this thread)...