Solar outdoor showerAugust 11th, 2011. Post by Quinta do Vale
The solar shower is finally up and working.
The heating system I first put together in May has proved itself workable. With a few adjustments of radiator position and the purchase of a self-standing garden shower that fits into the garden hose system I’ve used for the pipework, the system gives us enough hot water on a sunny day for anything between 2 (luxurious) and 4 (frugal) showers, but until recently the only way to use it was to stand on the bare earth out in the open. The quinta isn’t a particularly public place, but we all agreed we needed a cubicle to enhance our bathing experience …
The water heating works like this. We start the day with an empty tank on the terrace above. As soon as the sun has warmed the water in the radiator until it’s almost too hot to touch, we turn on the cold water supply which feeds into the bottom of the radiator. The pressure pushes the water up through the radiator, warming it on the way and, by a combination of pressure and convection, the hot water rises to fill the storage tank. Adjusting the flow gives the optimum water volume to achieve the desired heat. Since there is only the one feed into the shower, we aim for a water temperature around 40°C so no further mixing of water is necessary.
And here is the evolution of the cubicle …
Is this the final configuration of the shower? No. The present system works well, but it’s a bit too high-maintenance to be wholly practical. Since our water supply is just a hose in the stream, the cold water feed can be a bit variable and prone to air locks, requiring frequent adjustment of the tap to reset the rate the water passes through the radiator. This will be sorted once we sort out our water supply properly, but someone still has to remember to turn it on and off at the beginning and end of the day. And there are other issues.
The tank on the terrace above isn’t ideal for the purpose. It lacks insulation that would prevent heat loss once the sun is off it. It’s also plastic and prone to leaking where the thread got damaged by a brass fitting in its previous incarnation as the washing machine supply. And since it’s not designed for this purpose, there aren’t any other threaded connections I can use to experiment with indirect or recirculating heating methods and I’d like to try those out. A standard foam-insulated copper indirect hot water cylinder would be a lot better.