Solar hot water - works well for us.

[Franziska]

Hi,

I'm aware that there are these black bags you hang up to have 5l of warm water to take a very brief deck shower.

Still we wanted hot water below and not just 5 liters.

Being on a catamaran without inboard engines we were so far stuck with using electricity.

Now we tested an ordinary swimming pool solar heater with a circulation pump going through the heat exchange in our calorifier which is normally used for the cooling water circuit from the engine.
Piping connectors are under the wooden blocks and go through the deck to the 40l tanks heat exchanger.
The blocks hold the contraption also firmly to the deck.

We were at first sceptical but now it turns out it works very well on summer days with +22 degrees in the sun.
Very comfortable warm (45-50 degree C) showers in the bathroom, courtesy of solar.

Once per week we heat up to 80 degrees to keep germs at bay. Our tankwater has some bleach in it and runs through a carbon filter.

The swimming pool heater was 120€ last year.

See attached image.

[Chotu]

Very nice!!!

[noelex 77]

Cool

What circulation pump do you use?

[Franziska]

Originally Posted by noelex 77

Cool [emoji3]



What circulation pump do you use?

A cheapish one from Amazon.
https://amzn.eu/d/2hBAg6P

We'll see how it copes longterm with the elevated temperatures.

At night we switch the pump off.
This could be done also with a light sensor, but that would kick the circulation in also on overcast days. Not what we want.

The most difficult was to get all air out of the system.
As the heater is made from some sort of injection molded plastic, we did not dare to drill a hole at the highest point as we were unsure of how to get it really watertight again.
We might eventually install an automatic heating system air drain.

We running it successfully since 10 days, so the long-term verdict is still out.

But, it is working well so far.

[noelex 77]

Originally Posted by Franziska

A cheapish one from Amazon.

But, it is working well so far.

Thanks for the link.

Details of long term reliability would be useful if you have a chance to post your impressions further down the track.

[Franziska]

Originally Posted by noelex 77

Thanks for the link.



Details of long term reliability would be useful if you have a chance to post your impressions further down the track.

Will do that. If we should forget, don't hesitate to ask.

[toolbar]

Hi @Franziska - did the solar water heater continue to work as expected?

[Franziska]

On sunny days at anchor it works very nice.
If there is no cold draft underway it works also when sailing.

We are now in sunny southern Portugal.

Would we install it again? Yes.

[senormechanico]

We did a similar system on our Lord Nelson35, using a March pump. It was a 12 volt, food grade pump with magnetic drive. The pump gave us no problems at all.