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@12robot345 I did not evacuate the copper tube, I just heated the acetone some to drive the air out, nit the same thing at all. I know about the vacuum in the evacuated tubes. And the size of the copper tube doesn’t matter, as the insulation value of the vacuum is so good that all the heat (not solar at this point) goes into the smaller tube as I have the copper scrub pads as conductors. This enables using less costly copper, and is the way they are made commercially. Forget fluid thru the tubes
Okay, quick Engineering tip: Evacuating the inner copper tube is really a waste of time. The vacuum you’re interested in is the vacuum between the glass tube and the copper tube. you want that so you don’t lose the solar heat back out to the environment through conduction. A better plan: bigger copper tubes painted black. More surface area to absorb solar radiation. Pass fluid through tubes. Use anti-freeze so it doesn’t freeze, and so the pipes don’t corrode. Good luck!
How did you decide on 8 cc’s of Acetone? I am sure this is one of those things where more is NOT better. I can see where an optimum amount, if exceded, would rupture the tube.
I appreciate the specific information. I understood the heat tube you make, and how it goes into the vac tube, but I didn’t see how you attached your heat tube to the manifold, where it “gives up its heat”. Thanks for the vid.
@sundug69 I got it. Thanks so much.
solution246
February 19, 2012 at 4:18 am
@solution246 Lots of places, but for some reason I cannot post links here, just do a search
sundug69
February 19, 2012 at 4:46 am
Where can one get an evacuated tube?
solution246
February 19, 2012 at 5:20 am
I have no way of knowing
sundug69
February 19, 2012 at 5:22 am
How many BTU’s per panel? Thanks, great vid.
adxoplo
February 19, 2012 at 6:14 am
@12robot345 I did not evacuate the copper tube, I just heated the acetone some to drive the air out, nit the same thing at all. I know about the vacuum in the evacuated tubes. And the size of the copper tube doesn’t matter, as the insulation value of the vacuum is so good that all the heat (not solar at this point) goes into the smaller tube as I have the copper scrub pads as conductors. This enables using less costly copper, and is the way they are made commercially. Forget fluid thru the tubes
sundug69
February 19, 2012 at 6:38 am
Okay, quick Engineering tip: Evacuating the inner copper tube is really a waste of time. The vacuum you’re interested in is the vacuum between the glass tube and the copper tube. you want that so you don’t lose the solar heat back out to the environment through conduction. A better plan: bigger copper tubes painted black. More surface area to absorb solar radiation. Pass fluid through tubes. Use anti-freeze so it doesn’t freeze, and so the pipes don’t corrode. Good luck!
12robot345
February 19, 2012 at 6:54 am
LOL, that sounds like one of those exciting moments of science thru experimentation.
1foxtrot70
February 19, 2012 at 7:13 am
Trial and error, and the error can get dangerous. Instead of rupturing the tube, the bulb blew off and went completely over my house!
sundug69
February 19, 2012 at 8:02 am
How did you decide on 8 cc’s of Acetone? I am sure this is one of those things where more is NOT better. I can see where an optimum amount, if exceded, would rupture the tube.
1foxtrot70
February 19, 2012 at 8:08 am
Nice video….
matrixm777
February 19, 2012 at 8:19 am
Thanks
toadabc
February 19, 2012 at 8:49 am
I used copper anti seize paste to improve the thermal transfer from bulb to fitting.
sundug69
February 19, 2012 at 9:11 am
My other videos show that the bulb slides into a coupler fitting, which is soldered to the manifold pipes. The bulb is not soldered to the coupler.
sundug69
February 19, 2012 at 9:41 am
I appreciate the specific information. I understood the heat tube you make, and how it goes into the vac tube, but I didn’t see how you attached your heat tube to the manifold, where it “gives up its heat”. Thanks for the vid.
toadabc
February 19, 2012 at 10:06 am