Third test of solar distiller prototype-2

I reported on the second test here:

http://bkhome.org/news/201906/2nd-test-solar-water-distiller-prototype-2.html

For comparison, here is a test of the "gold standard", a Carocell 1000:

http://bkhome.org/news/201906/testing-f-cubed-carocell-1000-solar-distiller.html

Today, Tuesday 2nd July, 2019, Perth, Western Australia, mostly sunny, more rain coming later in the week, so decided to do another test. For this test, have stuck two layers of cardboard on the bottom of the panel to reduce heat loss.

Got going at 9.25am. Mostly blue sky, a few wispy clouds, ambient temperature 12 degC, sun intensity 760 W/m2. It seems to be slow to "get going" and producing any output, and there was mistiness on the inside of the glass (internal moisture from the previous test), and I wonder if that was a factor?

10.30am. Ambient 16 degC, sun 820 W/m2, front temp 40 degC, back 25 degC. Still hardly any water out. Sky still mostly clear.

12.40pm. Sun 925 W/m2, front 57 degC, back 32 degC. A lot more clouds in sky, maybe up to 1/3 of sky, moving, so sometimes sun goes behind one.

2.07pm. Ambient 20 degC, sun 810 W/m2, front 47 degC, back 33 degC.

3.00pm. Stopped. Distilled water collected: 0.75 litres

OK, the test of the Carocell panel did have continuous sun, no clouds, so had that advantage. However, allowing for the different sizes, if my distiller had been of the same efficiency, I would have expected about 1.5 litres for today's test.

But, got half that. So, not happy with the design. My distiller is probably comparable with other DIY efforts out there, but I want to do much better. What I would really like to achieve is about 2 litres per day, mid-summer, as that is a minimum in a survival situation, for one person.

It does seem that the two-pane design of the Carocell is the way to go. I didn't do this before, as there are construction difficulties, and I went for the simpler construction. Now going to rethink the design. Will probably remove the prototype #2 DIY plans. 

Tags: nomad