Solar shower update

Now that the winter has subsided, we decided it was time to turn on our solar shower again. A system that you can read more about here.
The system was turned on during the April working weekend, and two WOTters actually enjoyed a (still very cold) shower, a very welcome surprise after all the mud that was picked up at the other activities 🙃.

At an association night (Wednesday the 10th of April) we noticed two problems with the system.
-The water temperature was rising unexpectedly fast on Saturday and Sunday (for the sun intensity those days) and dropping too fast at nights.
-The pump failed to switch on on Monday and Tuesday. The system thinks it switched on the pump but the return-line temperature was not following the collector temperature. Which also meant the tank-temperature was not increasing on those days.So that Wednesday we checked the water level of the tank and sure enough the tank was almost empty, during dinner we let the tank fill up. And we used the bottom flush of the tank to try to flush some rust out of the system, which might have been blocking the pump.

We were hoping this would work, but during the following days, we noticed that the pump still was not switching on correctly. On some days it was (like Saturday the 12th of April), but on other days it was not. We can however see that the tank now heats up and cools down slower than it did when it was not completely filled.

Here you can find a graph displaying the data that is measured live from the solar shower system. This graph shows the temperatures of various sensors and the time the pump was on for every 10 minutes.
-The pink line shows how long the pump was on, the pump cycles on automatically when the collector temperature is higher than the tank temperature.
-The dark-blue line shows the temperature of the collectors, it quickly rises if the sun is shining.
-The red line shows the temperature of the water flowing out of the collectors and into the tank.
(This means it follows the collector temperature while the pump is on but the temperature quickly drops towards ambient once the pump has shut off)
-The light-blue and yellow line show the actual water temperatures in the isolated storage vat this is the water that is used to heat the shower water through a heat exchanger.

On Monday the 14th of April we flushed more rust out of the pump, this time by actually manually disconnecting the pump and running it with some clean water. This did not seem to work, because on the 18th the pump was jammed. On the 23th a small hole was found in a pipe and had been welded shut, this explains why the tank was as good as empty during the working weekend. The pump was replaced with another one on the 24th and this seemed to have helped, because the pump has been functioning every day up to the day of writing (the 3th of May). Since the 29th of May the days kept getting warmer and on the 1th of May the tank was at a temperature of 45°C and someone had a nice and warm shower 😊.

One Response to “Solar shower update”

  1. Michail says:

    What a great use of pictures! The two graphs are clear and I can read everything on it. They also show how the graph should look when the pump works and when it doesnt work correctly. The pictures in between help break up the text, just WOW. I am amazed by this amazing person who wrote this blog post!

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