Help with pump for rimstar system

[Mcintosh1964]

I have a small Intex 10' diameter 1000 gallon pool! These Intex pool come with tiny cartridge filters/pumps that can bairly keep up with the pool cleaning.
After experimenting with a 360' coil of irrigation tubing on my south facing flat roof I have decided to copy the rimstar system (http://rimstar.org/renewnrg/solar_po..._fp.htm)system using 6 500' coils.
Here is the problem, I need an seperate pump to accomplish this and my roof is 18' directly above the pool.
I think after all the reading I've done that I have a good understanding of the plumbing,bypass,headers, returns and how they all function together but I am stuck at the pump integration.
Could someone help me on the pump sizing? Should I use a "pool filter pump" or is there something smaller that will have the head night I need. I am concerned because the 1 1/2" pipe will leave the pump and go straight up 18 feet make a 90 degree turn and enter the feed header.
I'm not really concerned about the electricity cost because my calculations have me feeding the pool with about 30C( 86 F ) water from the collectors at a rate of 8 gallons per hour. I would be sending the complete water volume of the pool thru the collectors in 125 minutes.
Critique, suggestions and help would be greatly appreciated.

[Mike90250]

You may want ot look for a circulation pump for a "drain back" solar water heater system. They are designed to pump uphill to refill roof collectors after draining back on a chilly night. Just make sure to pick one with the head and flow rate you want.

[Mcintosh1964]

Thanks Mike, I'll google that and see what comes up!

[mikethestig]

Hi I am heating a 14 ft round pool 2800 gal and I use a 1/2 horsepower submersible pump from harbor freight. I don't know if they exist in Germany but I hope so
its rated at 1800 gal hr and a lift of 22 ft . I know I don't get the rated flow because I use garden hose as my supply and 1 1/6 sump pump tubing as my return but there seems to be more than enough water on the roof. I cobbled this all together with things I had around the house but in the warm days of summer it keeps the pool at 84 degrees it started at 73. i use a outdoor timer and bring the pump on at 9 and off at 6 this was my first attempt and it will be more refined next year when i figure out how to zone the system and only send water to the panels that are in the sun. I have a lot of tree cover

[Mcintosh1964]

Hi I am heating a 14 ft round pool 2800 gal and I use a 1/2 horsepower submersible pump from harbor freight. I don't know if they exist in Germany but I hope so
its rated at 1800 gal hr and a lift of 22 ft . I know I don't get the rated flow because I use garden hose as my supply and 1 1/6 sump pump tubing as my return but there seems to be more than enough water on the roof. I cobbled this all together with things I had around the house but in the warm days of summer it keeps the pool at 84 degrees it started at 73. i use a outdoor timer and bring the pump on at 9 and off at 6 this was my first attempt and it will be more refined next year when i figure out how to zone the system and only send water to the panels that are in the sun. I have a lot of tree cover

Thanks for the reply,right now I am doing the exact same thing using a submersible pump! I only have the one coil and when I do not restrict the flow I get a maximum of 6.6lpm (1.74 gpm). I know that the minute I add the next 500' coil the friction( dynamic head) will be so much as to stop all flow! The main problem is that it is dangerous to swim in a pool with a running sump pump! The risk of electrocution is to high! I'm still looking for the type and size pump I will need to feed my suc 500' could in parallel.

[skeeter_ca]

Wow, six 500' coils for 1000 gal pool. Seems like a bit of overkill. What kind of sunlight do you get during the summertime? What diameter of irrigation tubing are you using?

skeeter

[skeeter_ca]

Never mind, just found your other thread with a description of you system.

skeeter

[Mcintosh1964]

Never mind, just found your other thread with a description of you system.

skeeter

Hi Skeeter, overkill? I look at it from the perspective of " time to heat". We know that at some point the length of the coil becomes innificient. Everything I've bin reading pretty much says to place coils in parallel.
500' is very long and once I get my first coil completed I will collect data on temperature and flow rate to see exactly what difference the 140' feet make. The rainbird T-63 $45 Amazon prime is pretty cheap.
I live in Frankfurt Germany and the city that comes closet to us in regards to weather would be Seattle Washington. Summers are short and summer evening temperatures are cool. I hope that with the amount of coils running In parallel I will be able to get the temperature up within a couple of hours.

[skeeter_ca]

Not saying 500' coils won't work but it seems most successful systems use between 180' and 250' of tubing. Anything above that seems to be wasting hose. And yes they should all be ran parallel from a common header. Usually they are on a 4'x4' mounting board of some type. What size of a coil is there with 500' of tubing? Just having them laying on the roof would also work but just make sure they are nice neat coils, not just thrown up there laying all over and across each other. At that latitude I would start with 8 panels. Just my 2 cents. Hope it all works out for you.

skeeter

[Mcintosh1964]

Not saying 500' coils won't work but it seems most successful systems use between 180' and 250' of tubing. Anything above that seems to be wasting hose. And yes they should all be ran parallel from a common header. Usually they are on a 4'x4' mounting board of some type. What size of a coil is there with 500' of tubing? Just having them laying on the roof would also work but just make sure they are nice neat coils, not just thrown up there laying all over and across each other. At that latitude I would start with 8 panels. Just my 2 cents. Hope it all works out for you.

skeeter

My roof is a black rubber roof! My 360' test coil is laying directly on the roof andvis wound very loosly but it's in a circle( but not a pretty one). I saw a post in another site where small pvc pipe( I think 1/2") was glued together in a cross and the tubing was wound in between that! It looked very nice and I think I may copy that! If I can find that link I'll post it.
500' coil, you may be rite! I'm new at this and experimenting at the moment! When we go to water parks or indoor public pools we have found that the most comfortable water temperature that we enjoy is 33C ( 89F). My thought is that I will use as much coil as needed to get my output to that temperature and then multiply the coils to get the flow rate that's needed to turn over the pool water in 2 to 3 hours! Having a 1000 gallon pool I was thinking that 6 coils with each coil getting 1.6 gpm gives me almost 10gpm out of the system! I have no data to support this except what I get out of my 360' coil! I appreciate your advise and after I hook up the 500' coil I'll let you know what flow and temps I get!
I'm actually in Albany NY on business and will not be returning home till the 15th so my testing with the new coil is on hold for a couple of weeks!

[J.P.M.]

Has anyone on this thread checked out builditsolar.com and perhaps avoid reinventing the wheel ?

[Mcintosh1964]

Has anyone on this thread checked out builditsolar.com and perhaps avoid reinventing the wheel ?

Hello J.P.M, yes, I have spent a great deal of time at Builditsolar and actually contacted Gary for help in calculating the dynamic head of my proposed system! I'm a little confused as why you would say "reinventing the wheel". I am copying a system that everyone on every forum or website seems to have a link to! The system using 6 coils in parallel seems to be one of the most popular ones I've seen! The only difference is I'm installing them on a 770 square foot, flat, south facing roof which is already black! And, I was increasing the length of my coils to 500'.
I would really like to hear your opinion on why you consider this "re-inventing the wheel". I did mention in a previous post that I have detailed data on entry and exit temperatures with different flow rates for my 360' coil. Is there something you disagree with or do you consider increasing the length of my test coil to 500' and getting new data on flow rates and temperatures "reinventing the wheel" or a waist of time? I have been unable to find the exact data I'm looking for on any web site or forum.
John

[J.P.M.]

Hello J.P.M, yes, I have spent a great deal of time at Builditsolar and actually contacted Gary for help in calculating the dynamic head of my proposed system! I'm a little confused as why you would say "reinventing the wheel". I am copying a system that everyone on every forum or website seems to have a link to! The system using 6 coils in parallel seems to be one of the most popular ones I've seen! The only difference is I'm installing them on a 770 square foot, flat, south facing roof which is already black! And, I was increasing the length of my coils to 500'. I would really like to hear your opinion on why you consider this "re-inventing the wheel". I did mention in a previous post that I have detailed data on entry and exit temperatures with different flow rates for my 360' coil. Is there something you disagree with or do you consider increasing the length of my test coil to 500' and getting new data on flow rates and temperatures "reinventing the wheel" or a waist of time? I have been unable to find the exact data I'm looking for on any web site or forum. John

My apologies. Forget I brought it up. Have fun.

[Mcintosh1964]

My apologies. Forget I brought it up. Have fun.

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!

[skeeter_ca]

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