logo elektroda
logo elektroda
X
logo elektroda
Advanced Search
logo elektroda

Solar collector - heating water in a small pool

DJCheester 66540 45

TL;DR

  • A homemade solar collector heats water for a small children's pool using a garden hose, a 12V bilge pump, and a glass-covered insulated box.
  • A 100 cm x 100 cm wooden drawer-like frame is lined with 5 cm polystyrene, a black sheet, and about 50 m of 1/2-inch black hose under glass.
  • The pump draws about 1.6 A at 12 V, and the collector raises inlet-to-outlet temperature by 3–6 degrees.
  • In a green pool 180 cm in diameter with 10 cm water depth, the water reached over 35 degrees.
  • The 12V pump cannot run continuously at full power, so it is fed directly from a 10W solar panel; winter draining remains unresolved.
Generated by the language model.
ADVERTISEMENT
Treść została przetłumaczona polish » english Zobacz oryginalną wersję tematu
Report a violation of the law
Reply Cool? Ranking DIY | New topic
Notify about new articles
📢 Listen (AI):
  • #31 18864209
    btxxrv750
    Level 10  
    A question from a slightly different barrel:
    what effect will the use of a 3-pane window in the DYI panel have compared to a single-pane window?
    I designed a panel on the OSB board, including 100 meters of irrigation pipe fi25. Yes, I know, there could be a better pipe. But the question about the glass!
  • ADVERTISEMENT
  • #32 18864281
    Rezystor240
    Level 42  
    btxxrv750 wrote:
    what effect will the use of a 3-pane window in the DYI panel have compared to a single-pane window?


    If we assume that the windows will be clean, it's probably nothing. It will be the same as with one glass.
  • ADVERTISEMENT
  • #33 18864404
    DJCheester
    Level 27  
    Hello

    A triple-pane glass is possible - unless it has filters blocking some part of the light - so a single pane is a good solution because its task is to penetrate the rays into the hose and block the heat so that it does not go up and that the wind does not cool the hose.

    The hose and the whole structure are best painted black and then covered with a glass.

    Give me some photos of your construction.
  • ADVERTISEMENT
  • #34 18864591
    metalMANiu
    Level 21  
    Ha ha, I knew the topic would come back, just a few hot days is enough and everyone starts looking :)
    I am also seriously thinking about making a small (min. 1 m2) solar collector.
    Of course, I want to get all the materials from what I already have.
    As for the glass, I have a small choice:
    - use a few small panes from the greenhouse (100x60cm each)
    - use the glass from the table, BUT with rounded corners (140x80xm)
    Is it a better idea to combine several panes into one pane, or is it easier to use the large one?
    Allow me to insert photos from the construction site in this topic (although I'm beginning to doubt that I will make it before the end of this season).

    greetings
    Mariusz
  • #35 18864685
    SylwekK
    Level 32  
    metalMANiu wrote:
    Ha ha, I knew the topic would come back, just a few hot days is enough and everyone starts looking

    And that's the strangest thing :) I have not heated the water at all for several days. In the morning I have not less than 29 degrees, and in the afternoon usually 32-33 degrees, which I will stretch under the cover.
  • #36 18865528
    DJCheester
    Level 27  
    Hey, of course, paste photos - as for the glass you can order to size - it's not that expensive - I did - I know that there were versions of the collector made of plexiglass, the ones with channels also warmed up nicely and nothing happened with the plexiglass from the heat.

    As if what is it, go ahead - the collector works for me for a few nice years, removed for the season and works quite well, the only thing I changed is the 30W solar panel I put on the pump, the water circulates faster and the water cools faster.

    It is true that the pump at 12V should not work constantly, but in my case with a 30W panel in the sun and the pump connected to it, the voltage is about 8.5V and it works like that and nothing is happening to the pump.

    Greetings ....
  • #37 18865840
    btxxrv750
    Level 10  
    DJCheester wrote:
    Hello

    A triple-pane glass is possible - unless it has filters blocking some part of the light - so a single pane is a good solution because its task is to penetrate the rays into the hose and block the heat so that it does not go up and that the wind does not cool the hose.

    The hose and the whole structure are best painted black and then covered with a glass.

    Give me some photos of your construction.


    Well, it looks like the picture.
    Solar collector - heating water in a small pool

    OSB 12mm (2500x1250mm) reinforced with a batten on the bottom, painted black mat, and 100 running meters (or actually 96 entered) of the irrigation pipe fi25 = 30l of water. Connected to a circulation pump and it flows slowly. At the moment, I run the water every hour for 15 minutes with an ordinary time controller, not a thermostat.
    I wonder what the difference will be after using the glass. I have a piece of a window available for free: one triple pane, 2470x1000mm, so almost all of it.
    They sang me about PLN 600 for plexiglass, so sorry but no. It is supposed to be at cost.

    The pool has a capacity of 7-8 m3. I do not really hope that I will be able to heat the water properly, maybe 1-2 degrees Celsius. I treat the construction of a solar panel more as gathering experience to someday make DYI for DHW heating :-D
    Well, thanks for all the advice!
  • #38 18865855
    Rezystor240
    Level 42  
    Cover it with the glass, and seal it tightly. The effect should be better. The second thing is, the scrolls cannot overlap each other because it's nonsense.
  • ADVERTISEMENT
  • #39 18866183
    metalMANiu
    Level 21  
    Rezystor240 wrote:
    The second thing is, the scrolls can't overlap each other because it's nonsense.

    Oh dear, only 2 coils came down because something "didn't bang" ;)

    btxxrv750 wrote:
    OSB 12mm (2500x1250mm) reinforced with a batten on the bottom, painted black mat, and 100 running meters (or actually 96 entered) of the irrigation pipe fi25 = 30l of water.

    1. How much can all this weigh when empty of water?
    2. How do you carry it?
    3. Do you think that in a similar budget it is possible to find a pipe that could be better "packed" and filled with it the entire (or almost the entire) surface of the collector?

    Maybe a single-panel steel radiator would be cheaper, but also better than 100m of such a thick pipe. Link to the 60x140cm radiator (new) for PLN 100: https://allegro.pl/oferta/grzejnik-panelowy-quinn-600x1400-c11-jednopanelowy-9576317626. In my opinion, such a heater:
    - it is much lighter than a solution with a hose (both with water and "dry"),
    - uses the surface much more efficiently,
    - easier and faster assembly.
  • #40 18866210
    bambus94
    Level 34  
    As for covering the collector with the tube with glass, a man from the east checked it:
    [youtube]https://www.youtube.com/watch?v=gHjbdaSsk-g?t=240[/youtube]

    The collector from the radiator seems to be a nice solution, and here it is similar, I do not know how price it is.


  • #41 18866956
    btxxrv750
    Level 10  
    metalMANiu wrote:
    Rezystor240 wrote:
    The second thing is, the scrolls can't overlap each other because it's nonsense.

    Oh dear, only 2 coils came down because something "didn't bang" ;)

    btxxrv750 wrote:
    OSB 12mm (2500x1250mm) reinforced with a batten on the bottom, painted black mat, and 100 running meters (or actually 96 entered) of the irrigation pipe fi25 = 30l of water.

    1. How much can all this weigh when empty of water?
    2. How do you carry it?
    3. Do you think that in a similar budget it is possible to find a pipe that could be better "packed" and filled with it the entire (or almost the entire) surface of the collector?

    Maybe a single-panel steel radiator would be cheaper, but also better than 100m of such a thick pipe. Link to the 60x140cm radiator (new) for PLN 100: https://allegro.pl/oferta/grzejnik-panelowy-quinn-600x1400-c11-jednopanelowy-9576317626. In my opinion, such a heater:
    - it is much lighter than a solution with a hose (both with water and "dry"),
    - uses the surface much more efficiently,
    - easier and faster assembly.


    1. The weight of the dry panel is about 30 kg.
    2. Due to the dimensions, two people are needed, but then no problem. I set up once at the beginning of the season and there will be one shelter after the season. A friend suggested mounting wheels - also not stupid.
    3. Yes, it seems to me that, for example, a 16mm pipe would be better, preferably alupex, because it is easier to form. Then the surface would be better filled, but again this pipe will need about 250m to get 30l, so it will be more expensive, and for that you need a more powerful pump to push it through.
    On the other hand, a pipe diameter of 25mm is quite a lot of water to be heated, assuming a continuous flow ... So here the 16 will work better.

    A panel radiator may be cheaper, but its capacity is about 5 liters, so I would have to put 6 of these (I have 30l in the pipe)! And this is a cost several times higher than that of a pipe. Additionally, space for 6 heaters: - /
    At the moment, the whole thing cost me about PLN 400, including the pump, so pretty good.

    This movie in Russian is probably cool, but it would be good to understand something :-D
  • #42 18866972
    bambus94
    Level 34  
    This is not about water capacity, but about the surface that the sun is looking at. Therefore, such a panel heater can be as good a solution as a tube.
  • #43 18867342
    DJCheester
    Level 27  
    Cool collector cover with glass and do not worry, it works for me, you can fold several panes, as long as the whole is relatively tight, then warm air under the glass, gray pipe and not escaping on the sides ;)

    greetings ;)
  • #44 18869840
    True_Brujah
    Level 13  
    The power of this solar collector based on a hose, despite its 30l capacity, will have a rather poor efficiency. In the best winds, the sun is used only for 1/3 of the snake's surface area (this is where the sun shines). The collector based on a panel heater is light, easy to empty of water during the winter, you can make a detachable multi-element one depending on the required power. I'm not saying it's a bad idea, but it's better. The radiator is metal, thin-walled and has a low heat capacity and will transfer heat to the water faster. PVC (because hoses are probably made of it) is not great when it comes to heat transport.

    Taking into account all the data provided, the surface area of this pipe with a length of 100 m gives us 7.5 m2. If we assume that 1/3 (optimistic) of this hose is exposed to sunlight, it gives us 2.5 m2 of water heating area. The 3 new heaters given 2 posts above give a similar area - 2.52 m2 with a smaller size and lighter structure. In winter they are easier to hide, you can put the whole structure on quick-couplers. And you definitely need to cover both structures with glass for a better effect.

    After all, the idea of using a hose is interesting.
  • #45 18870422
    DJCheester
    Level 27  
    Hello

    I have a collector from the first thread for a few years I do not have a small pool and I did not mean to "boil" the water, only heat it slightly, the collector is sufficient for a small pool, these 5000 l pools will not heat up for sure - here the colleague above is certainly right with the heater As for the problem of emptying the hose for the winter, I do not have any problem, I simply blow the water out of the hose with the cooling unit and hide it for the winter after the season.

    For a larger pool, I would certainly improve the structure by using a few panel heaters closed under the glass - and painted black mat.

    Greetings ...
  • #46 21122239
    lesiu2705
    Level 1  
    Hello, I have a question, what is the best way to connect the fi 16 pipe to the pump spigot, which I think is fi32?
Reply Cool? Ranking DIY | New topic
Notify about new articles
📢 Listen (AI):
Report a violation of the law

Topic summary

✨ The discussion revolves around a DIY solar collector designed to heat water in a small pool. The original poster shares their experience and construction process, inspired by previous projects on the Elektroda portal. Various methods for inflating the pool are discussed, including using compressors and manual pumps. Participants suggest improvements for the solar collector, such as painting hoses black to enhance heat absorption and using panel heaters instead of hoses for better efficiency. Calculations for determining the required size and flow rate of the collector are also shared, along with considerations for materials and construction techniques. Concerns about the potential for plastic odors in heated water and the durability of materials under UV exposure are raised. The conversation concludes with practical advice on connecting pipes and ensuring proper water circulation.
Generated by the language model.
Today's popular

FAQ

TL;DR: A 1 m² DIY hose-and-glass solar collector yields about 1.68 kW of heat in noon sun [Elektroda, metalMANiu, post #15775491]; “the joy of a child babbling in ‘soup’ – priceless” [Elektroda, SylwekK, post #15776906]

Why it matters: The low-cost build warms small pools safely without mains electricity.

Quick Facts

• Typical inlet-outlet rise: 3–6 °C per pass [Elektroda, DJCheester, post #15774489] • Flow rate: 4–10 L min⁻¹ with 10–30 W 12 V pumps [Elektroda, DJCheester, post #15774489] • Power density: ~1.7 kW m⁻² at 6 °C ΔT and 4 L min⁻¹ [Elektroda, metalMANiu, post #15775491] • Build cost: ≈ PLN 400 for a 2.5 m² panel incl. pump [Elektroda, btxxrv750, post #18865840] • Safe voltage: 12 V DC; avoid 230 V unless RCD + IP67 gear [Elektroda, DJCheester, post #15774489]

How does the garden-hose solar collector heat pool water?

A 12 V submersible pump pushes pool water through 50–100 m of black hose laid on insulation and sealed under glass. Sunlight heats the hose; the warmed water returns to the pool. When clouds arrive, the pump slows or stops, preventing heat loss [Elektroda, DJCheester, post #15774489]

What hose size and length give the best result?

Builders report good balance with 1⁄2 inch (≈ 12 mm) hose, 50 m per square metre of panel. Longer runs raise output but need stronger pumps; 100 m of 25 mm hose holds 30 L and suits 8 m³ pools [Elektroda, DJCheester, #15774489; Elektrode, btxxrv750, #18865840].

How much can the collector warm a kiddie pool in one day?

With full sun a 1 m² unit raised a 180 cm-dia, 10 cm-deep pool from 25 °C to over 35 °C between morning and 16:00, a 10 °C gain [Elektroda, DJCheester, post #15774489] Larger 5 m³ pools typically gain 1–2 °C per sunny day when scaled proportionally.

How do I calculate the collector’s heat output?

Use P = 4 190 × flow (L s⁻¹) × ΔT (K). Example: 0.067 L s⁻¹ at 6 K gives 1 680 W [Elektroda, metalMANiu, post #15775491] This aligns with the 1 000 W m⁻² solar constant [NREL, 2023].

What’s the simplest way to drain the hose for winter?

  1. Disconnect the pool end.
  2. Blow compressed air until bubbles exit the inlet.
  3. Tilt the panel so residual drops leave. Users empty 50 m coils in under two minutes with a fridge-compressor blower [Elektroda, tomek.ch, #15774738; DJCheester, #15781415].

Does heated water pick up a plastic taste or smell?

No issues were reported after daily water changes; smell remained neutral [Elektroda, DJCheester, post #15776201] Use food-grade or garden-grade hoses rated ≥ 60 °C for peace of mind.

Can I build with flat panel radiators instead of hose?

Yes. Three 60×140 cm C11 radiators (≈2.5 m²) match the hose surface, weigh less, and empty easily. Metal skins transfer heat faster, but cost is higher (~PLN 300 each) [Elektroda, True_Brujah, post #18869840]

Will tripled glazing improve performance?

Only if the panes lack low-E coatings. Extra glass increases reflection losses by ~8 % per sheet, so a single clear pane usually wins [Elektroda, Rezystor240, #18864281; Solar Glazing Losses].

How can I inflate the pool without burning cheap compressors?

Use a double-action hand bellows or connect a vacuum-cleaner exhaust; both fill a 2 m pool in <10 min [Elektroda, prosiak_wej, #15774771; ketch, #15779099]. A bargain 12 V car compressor overheated and failed after five minutes [Elektroda, DJCheester, post #15774489]

What happens if the pump stops under strong sun?

Stagnation can overheat the hose above 70 °C, softening PVC and shortening life. A solar-powered pump self-regulates: when light drops, circulation stops, preventing reverse cooling and damage [Elektroda, DJCheester, post #15774489]
Generated by the language model.
ADVERTISEMENT