I think that we are buying two different types of piping. I bought the kind that is used for hot and cold water supply. I know that it was overkill, but it seemed that it would never kink when bent. I was afraid that the black piping used for irrigation would. If I get 3-4 per 500 ft, even if I buy two rolls eventually, the cost of all six panels will still be reasonable. IMO. Others may disagree.
Please help with my DIY solar heater
- Thread starter aquamarine
- Start date
- May 26, 2009
- 46
True, the black PE pipe can kink if you wrap it to tight and are not careful. Is your pipe still black?
The hose was blue. One can of spray paint later and it is flat black along with the rest of the inside of the "box". I could post a pic if there is any interest...
spdas
0
- Jun 17, 2009
- 35
Aloha, not to burgle this thread, but I have a couple of questions about the DIY panels to throw out for additional thots.
First, I have ordered 2 4x20 Sunsavers, because I want LOTS of heat potential to swim year round here in Hawaii. But I have a 500' x1/2 coil already working and room for 2 more 500' on the flat 8x20' roof so will continue my DIY project. (will be able to give a good A/B test results too) . So...
1: I will be splitting the 500' into 10 x 50' lengths, and make a 2' diameter manifold
2: Does the manifold have to have a greater diameter than the sum of the 1/2" tubes? There will be 30 1/2" tubes, so would I need to go up to a 3" manifold. Volume for 30 1/2 is 5.90" Volume for 2" manifold is 3.14" and 2 1/2" is 4.91" and 3" is 7.07".
3: Would it better to use something like a 1/4 or 3/8" tube?
4: Any glue that will make a seal for PVC to Poly tubing?
Francis
First, I have ordered 2 4x20 Sunsavers, because I want LOTS of heat potential to swim year round here in Hawaii. But I have a 500' x1/2 coil already working and room for 2 more 500' on the flat 8x20' roof so will continue my DIY project. (will be able to give a good A/B test results too) . So...
1: I will be splitting the 500' into 10 x 50' lengths, and make a 2' diameter manifold
2: Does the manifold have to have a greater diameter than the sum of the 1/2" tubes? There will be 30 1/2" tubes, so would I need to go up to a 3" manifold. Volume for 30 1/2 is 5.90" Volume for 2" manifold is 3.14" and 2 1/2" is 4.91" and 3" is 7.07".
3: Would it better to use something like a 1/4 or 3/8" tube?
4: Any glue that will make a seal for PVC to Poly tubing?
Francis
A 2" manifold should be fine.
There is a tradeoff with pipe diameter. Smaller pipes mean better heat transfer, but more connections, lower flow rates, and higher costs. Most people go with 3/8", but 1/4" isn't completely out of the question.
There is a tradeoff with pipe diameter. Smaller pipes mean better heat transfer, but more connections, lower flow rates, and higher costs. Most people go with 3/8", but 1/4" isn't completely out of the question.
spdas
0
- Jun 17, 2009
- 35
Aloha, I am a bit lost in the debate of larger vs smaller pipe. I understand the theory of both. The "1/2"" pipe ID actually is .60 and the 3/8" id actually is .27, less than 1/2 the diameter!
I am going with 50' runs from header to header, not 20' so would your $ be on the 1/2" or 3/8"??
thanks
Francis
I am going with 50' runs from header to header, not 20' so would your $ be on the 1/2" or 3/8"??
thanks
Francis
- May 26, 2009
- 46
I used 3/4 myself at first, but also used 1/2 inch too. Personally I like the 1/2 inch best because it works just fine for me, and I can't get 38 or 1/4 without ordering and it costs a lot more for me to order it. Costs vs effectiveness vs time it takes to build vs space it takes up on my roof, I am comfortable using 1/2. 50' runs huh? Not a bad idea. I didn't think of making smaller coils than 100'. Let me know how they work out for you. Making smaller coils of shorter runs adds to the cost of all the fittings. It also adds more potential for leaks. For every coil, I use a 2" tee to connect to the manifold, a slip to threaded bushing to connect to the tee and allow the PE tubing push connector to thread into the tee. I put a clamp on each push connector just in case to prevent a leak. (god forbid the hose pops off while I'm not home. That's a lot of pool water to be spraying on my roof!) So with 2 tees, 2 bushings, and 2 PE connectors plus clamps, that's about $8 in connections per coils. That's an extra cost of $24 if I make my 200' foot coil of 1/2 inch into 4 50' coils. I didn't think I would see better performance to justify the extra fittings, money, and work.
spdas
0
- Jun 17, 2009
- 35
Aloha, re: the connectors. I can get 3/8 pipe and with 1/2" pipe thread with barb connectors that may or may not need a hose clamp. (or maybe I could use a tie wire ala aircraft safety wire)
OR
I got the 1/2" PVC to 1/2" irrigation tubing adapter and don't see why I cannot just drill into the header with drill press to make a very tight hole and push it in. It is about the same as the adapter above. I could chamfer the hole a tiny with a larger drill bit, bit to encourage the 1/2" irrigation tubing to fit a tighter hole. Maybe use a little clear silicon to slide in easier and help seal?
wadaya think?
Francis
OR
I got the 1/2" PVC to 1/2" irrigation tubing adapter and don't see why I cannot just drill into the header with drill press to make a very tight hole and push it in. It is about the same as the adapter above. I could chamfer the hole a tiny with a larger drill bit, bit to encourage the 1/2" irrigation tubing to fit a tighter hole. Maybe use a little clear silicon to slide in easier and help seal?
wadaya think?
Francis
The challenge with building a manifold is to get reliable connections that won't leak. I have no doubt that the method you just described will work most of the time, but you need to to work many times without any of them leaking. That is possible in theory, but it gets to be much more challenging/problematic.
spdas
0
- Jun 17, 2009
- 35
Aloha: Connections that don't leak..... and don't cost too much as compression fittings will make the cost way overboard and there is no glue for PE/PVC so I am trying:
1: drilling a 41/64" hole for the 1/2" irrigation tube (x33 tubes) and push fitting. It does not leak NOW but I fear that overtime with water heating and cooling the joint may become loose and start leaking.
2: I am going to try the following in the AM after I check sizes at Home Depot. Use a 1/2" copper pipe about 3" long and warm/heat it and should snuggly fit into the PE tube maybe up to 1"-2" deep. Then drill "about" a 1/2" hole in the PVC header and heat the copper tube and melt it into the PVC. This should make a drip free joint and cheap. Later if the PE to copper drips I can use a clamp. I have experience with PVC to copper heat/melt joints and they do NOT leak.
(hopefully the copper tube (either water or air/cond) will be the right size!
Francis
1: drilling a 41/64" hole for the 1/2" irrigation tube (x33 tubes) and push fitting. It does not leak NOW but I fear that overtime with water heating and cooling the joint may become loose and start leaking.
2: I am going to try the following in the AM after I check sizes at Home Depot. Use a 1/2" copper pipe about 3" long and warm/heat it and should snuggly fit into the PE tube maybe up to 1"-2" deep. Then drill "about" a 1/2" hole in the PVC header and heat the copper tube and melt it into the PVC. This should make a drip free joint and cheap. Later if the PE to copper drips I can use a clamp. I have experience with PVC to copper heat/melt joints and they do NOT leak.
(hopefully the copper tube (either water or air/cond) will be the right size!
Francis
- May 26, 2009
- 46
The only concern with using copper is that Chlorine is highly corrosive to metals. That is why you see most pool parts made of plastic. After a year or so, I wouldn't want to see your hair turn green from swimming in your pool! I would have to agree with JasonLion here that for the amount of work your doing, it might be worth your while to buy a commercial one. My coil design was cheap enough, works well, and didn't take me more than one weekend to put it all together, but doing all that work to build a manifold that might leak sounds like more hassle than I would take on.
spdas
0
- Jun 17, 2009
- 35
Aloha, I don't know why I am doing it. I have panels coming in on Friday, I guess the McGiver challenge. But thanks for the heads up on the copper, so I will try the push fit (#1) and if leaks then use a threaded connector with a barb. and optional clamp. Cost FYI will be about $300.00 (parts $150.00) the rest labor. But will end up with 1500' of 1/2" in 33x50' lengths and 2" headers.
francis
Edit. I have 66 connections to make and have found NO pre-made for even 10 connections (well actually I did find the 1 1/2 x 10). Like I said I can retrofit the holes if leaking to 1/2 pipe thread and use a barb/clamp for the PE tube side.
francis
Edit. I have 66 connections to make and have found NO pre-made for even 10 connections (well actually I did find the 1 1/2 x 10). Like I said I can retrofit the holes if leaking to 1/2 pipe thread and use a barb/clamp for the PE tube side.
launboy
0
Have you looked into a premade manifold? I know many hot tubs use them for their jets. It might actually end up costing less to buy the manifold, and you'll have the piece of mind that it won't leak!
P.S. I think it's a great idea to DIY things. I was originally going to buid my own panels, but found a GREAT deal on eBay. I was also going to DIY build my own Hot Tub, but found a hot tub on Craigslist for cheaper then I could build one.
This site has a few different types of manifolds for not much money. I'd bet for less than it would cost to build one. Link
Adam
P.S. I think it's a great idea to DIY things. I was originally going to buid my own panels, but found a GREAT deal on eBay. I was also going to DIY build my own Hot Tub, but found a hot tub on Craigslist for cheaper then I could build one.
This site has a few different types of manifolds for not much money. I'd bet for less than it would cost to build one. Link
Adam
spdas
0
- Jun 17, 2009
- 35
Aloha, all done and it works great!
1: used 2 2" headers and 33 1/2" x 45' tubes
2: NO LEAKS !!!
3: I used a hole saw and drill press to drill out the 66 holes
4: Used a 1/2"x1/2" joiner coupling that I turned down on my lathe to tightly fit the 66 holes made above
5: Bought irrigation 1/2" compression fittings that glued into the couplings @ .22 each
Total cost about $150.00 parts
Labor intensive and probably not as good as the Ebay panels (2 x 4x20' ones are coming tomorrow so will be able to A/B test the effeciency. So better idea to buy store bought panels unless $ is a real issue.
So what is the best flow/vs heat setting? I can adjust from 6gpm @ 2 degrees to 2gpm @ 6 degrees.
thanks
Francis
1: used 2 2" headers and 33 1/2" x 45' tubes
2: NO LEAKS !!!
3: I used a hole saw and drill press to drill out the 66 holes
4: Used a 1/2"x1/2" joiner coupling that I turned down on my lathe to tightly fit the 66 holes made above
5: Bought irrigation 1/2" compression fittings that glued into the couplings @ .22 each
Total cost about $150.00 parts
Labor intensive and probably not as good as the Ebay panels (2 x 4x20' ones are coming tomorrow so will be able to A/B test the effeciency. So better idea to buy store bought panels unless $ is a real issue.
So what is the best flow/vs heat setting? I can adjust from 6gpm @ 2 degrees to 2gpm @ 6 degrees.
thanks
Francis
launboy
0
spdas said:
Congrats on getting it up and running!
Best setting is 6gpm @ 2 degrees. You want the highest flow and the lowest temp gain. The cooler the water stays in the panels, the more efficient they are.
Adam
spdas
0
- Jun 17, 2009
- 35
Aloha, I was surprised that my 1/8 hp filter pump that is drawing water from the 8' depth and pushing up another 8 feet to the roof through the heater is still able to put out 20 gpm. I got it adjusted now to flow 4 gpm to the panels and 15 gpm to the pool. No degrading after going through 1500' of 1/2" irrigation tubing. I got about 1 degree of temp increase in the pool after I got finished installing the tubes at 2pm. so tomorrow, hopefully will be sunny all day and will see what they will put out. But sun was directly overhead on tuesday here in Hawaii and I am on the sunniest side of Oahu, so we are getting max solar performance.
Francis
Francis