Help with pump for rimstar system

[J.P.M.]

No apologies needed!!! I'm very new to this and if someone suggests that I'm re-inventing the wheel then please at least link me to the particular article or explain why you think so! I'm trying to learn and asking for help!! I am unable to find any negative data on copying Ken Gordon's system, http://rimstar.org/renewnrg/solar_po...ter_diy_fp.htm And I am unable to locate any articles, data or examples of using longer coils. Actually, it seems that many DIY builders use multiple coils in a series/parallel configeration. When I've looked at that option the coil lengths in the series part exceed 500'. I have read and understand that as the water absorbs heat and continues to rise in temperature that the system becomes more inefficient, but I've been unable to locate data on what the optimal coil length should be. If there is anything your willing to share it would be greatly be appreciated!

Thank you for your service to our country. Since I usually tell folks how to build a watch when they ask me what time it is, and that often does little more than frustrate them, and as it seems you're doing this for the purpose of learning as much as heating something, I'll save us both a lot of aggravation and time and simply and respectfully suggest that for efficient heating, IMO, you'll be better off with a Fafco panel. On learning or getting answers: Back in the '70's I was in a similar situation to yours with respect to fooling around w/ solar thermal and also got so pissed at not finding much helpful info or answers that I returned to school and eventually wound up as a mechanical engineer designing pressure vessels, piping and energy systems for power plants, refineries, etc. You may get the same bug I got. Good luck.

[Mcintosh1964]

Thank you for your service to our country. Since I usually tell folks how to build a watch when they ask me what time it is, and that often does little more than frustrate them, and as it seems you're doing this for the purpose of learning as much as heating something, I'll save us both a lot of aggravation and time and simply and respectfully suggest that for efficient heating, IMO, you'll be better off with a Fafco panel. On learning or getting answers: Back in the '70's I was in a similar situation to yours with respect to fooling around w/ solar thermal and also got so pissed at not finding much helpful info or answers that I returned to school and eventually wound up as a mechanical engineer designing pressure vessels, piping and energy systems for power plants, refineries, etc. You may get the same bug I got. Good luck.

Thanks J.P.M. I've actually looked at the Fafco panels and the reason I decided that is was not an option for me is the cost of getting them to Germany! Adding shipping to the cost of the panel itself....😳
Even using 6 500' coils ( still need to test and collect data before deciding the lenght) my total cost for the coils will be $300 + a few dollars for the headers! I'll stick with the irrigation tube DIY system and keep playing with it till I get it right. Lol
Thanks for your reply!
John

[Mcintosh1964]

If you are still doing testing I suggest building two coils. One 500' and one 250'. Using the same flow rate for both, testing output temps to see if you do get much greater performance out of the longer coil. Would love to see the data on that at difference flow rates. I would think that unless the flow rate is a lot higher at the same temp increase it might not be worth it. Around 2gpm flow seems to be the norm for most applications.

Remember the goal is to only increase temp by 1-3 degrees with the highest flow as possible. The increase would be cumulative over time and maintains the highest temp desired. You are not trying to raise it all at once in one pass.

skeeter

I will actually do that. I cant help but thinking that the temperature increase will be significant.
But I will collect detailed data and pass it on.
As far as the size of the coil, I can't be sure at this point but we know from all the other DIY builders that they are getting about 200' on a 4x4 sheet of plywood. A 4' diameter has a circumference of a little more than 12 feet. So for every loop around your using 12' and the diameter increases by 2" on every loop. OK,
not sure what the formula would be to get the exact diameter but doing it in my head I come up with about 6.5 to 7 foot diameter coil.

[J.P.M.]

Thanks J.P.M. I've actually looked at the Fafco panels and the reason I decided that is was not an option for me is the cost of getting them to Germany! Adding shipping to the cost of the panel itself.... Even using 6 500' coils ( still need to test and collect data before deciding the lenght) my total cost for the coils will be $300 + a few dollars for the headers! I'll stick with the irrigation tube DIY system and keep playing with it till I get it right. Lol Thanks for your reply! John

You're welcome. Stay curious my friend.