DIY 1 Hour Solar Pool Heater

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Introduction: DIY 1 Hour Solar Pool Heater

About: I have a Scottish background, hence the username :) Many careers have led me to being a Tech Teacher, jeweller, diamond setter, landscaping, fences & decks, every computer job you can think of, restaurant …

I wanted to try an experiment with some black 3/4" PVC tubing I had. I spent 1 hour and a total of $5 as I already had the PVC, the tie wraps and the plywood. So here is a quick and easy way to raise your pool a few degrees each day when it's nice and sunny. This instructable is only for creating the solar collector. I will do another one having to do with tying it into your pool system.

TOTAL PARTS LIST

75 - 100 feet of 1/2" or 3/4" PVC tubing

25 - 40 8" tie wraps

25 - 40 1/4" x 1 1/4" wood dowels (optional)

4 x 4 sheet of 1/2" or 3/4" plywood

TOOLS NEEDED

drill with 1/4" drill bit

cutters for tie wrap

Step 1: Lay Out the Pattern

I used 3/4" tubing so my holes are 1" apart. Find the centre of your back board by drawing a line corner to corner from each side. They will cross in the middle. I started my holes 23" from the centre and drilled to 5" from the middle. Don't try and get any closer then this or your tubing will kink and screw up your water flow. Never do square corners as the kinking and restriction in water flow will defeat the extra tubing you will be able to fit on the board. Also do not put the tubing tight against the next coil as you want the heat to get at all sides of the tubing. More on this later. If you use 1/2" tubing then drill your holes using 3/4" separation.

The test version I made used about 70' of 3/4 inch tubing. There is aprox 52' wound on the board and the rest is to bring the water from the pool to the heater and back. To help you while laying out the tube I used 4 large wood lag bolts that I hand tightened into the 4th hole from the outside in each set of holes. This let me lay down 3 windings and keep them loosely in place while I put my 1st tie wraps through. You can use smaller tie wraps and wrap every winding, I used 8" and wrapped 2 at the same time. Do NOT tighten the tie wraps as you will need to adjust your windings and ensure proper spacing later. If you use individual tie wraps on every winding then you will not need the wooden dowels.

Step 2: Finishing the Solar Collector

Continue laying down the tubing until you have finished your collector. Once all the tubing is on the board adjust the windings so they are all even and not jammed up against each other, sticking up or otherwise messed up. The more evenly they are played out the better for overall heat collection.

The last step in my version is to insert the wooden dowels into the holes between each pair of windings. As I wrapped 2 tubes with 1 tie wrap there is an extra hole available. Hammer the dowel in and the spacing will be perfect. If you use individual tie wraps then you will have no extra holes and no need for the wooden dowels.

Once you are sure that all the tubing is speed perfectly tighten the tie wraps and trim.

To improve on the heat exchange you can add a 1 x 2 frame around the outside of your collector, paint the collector black and drop a 4 x 4 sheet of plexiglass on top. This will dramatically increase the efficiency of your solar heater by trapping the heat inside the box and preventing wind from calling it off.

To test the heater out I just jammed one end of the tubing into one of my pool inlets. I had a spare aluminum barb connector and that was enough to keep it in place. The temperature difference was 2-4 degrees and my pool went up 3 degrees in 1 afternoon. Do NOT run water through your collector once the sun goes down or you will be cooling your pool not heating it. I only run my filtration system for 8 hours each day, I do this from noon to 8 PM.

Step 3: Some Additional Notes and Things to Consider

Do NOT try and put this on top of a 2 story house as most pumps will not be able to drive the water that high without a lot of extra strain and work on the pump. If you have a pool house or shed then these are perfect locations to place a solar heater. Just keep in mind that the heater has some weight to it. Mine is only about 50lbs so no issue. Since this experiment worked very well I will be relocating this temporary heater to my pool house roof and tying it directly into the filtration system. I will post an instructable for that once I get it done. My pool house has brown shingles and heats up light a nuclear over so no need for boxing my solar heater. I will just need to adjust the time of my filtration to start running earlier.

There are several different versions of this that will also work very well. One uses a larger 1 1/2" PVC tube to carry the water to the collector which then splits off into 6 individual 1/2" tubes and then comes back into a 1 1/2" return. This would carry a much larger volume of water and could easily heat up a larger pool. Make sure your pump can handle it before trying this. The six individual 1/2" pipes can be layed out any way you like. Straight along the roof for 20 feet would let them pick up plenty of heat.

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Runner Up in the
PVC Challenge

Outside Contest

Participated in the
Outside Contest

2 People Made This Project!

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15 Comments

0
NotCook
NotCook

11 months ago

I just built this. I used 1/2" landscape watering tubing. I used about 100', and used a small 350gph pump to circulate the water. As suggested, I painted the board flat black. The surface gets very warm to the touch, until you turn on the pump. then it cools down quickly, but that is a function of how fast the water flows through it to draw off the heat. The heat still transfers. I find it comes out of the hose about 3 degrees F warmer than when it went in. That would take 25 hours to raise a 7500 gallon pool 3 degrees. Of course, as the input water heats up, it will continue to heat it up by 3 degrees. So far, in an 8 hour period, we did see a 2-3 degree increase, but part of that may have been just the sun heating the pool. It hasn't helped that we have had only one really sunny day since I made the device. I was hoping for more, but it may be necessary to do more such panels to get better results. I might also try the box and plexiglass next to capture more heat.

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mickryobe
mickryobe

7 years ago on Step 2

Would surfacing the plywood with a reflective material such as heavy aluminum foil increase the unit's ability to collect heat?

Mickey

0
NotCook
NotCook

Reply 11 months ago

Reflective, like foil, would have the opposite effect from what you want. It would reflect the heat away instead of absorbing it. As others have suggested, paint it matt black so it absorbs as much heat as possible.

0
RoxannD
RoxannD

7 years ago on Introduction

I did this and I added two things that were a little different. I painted the wood black and then put a window on the whole thing. The result was great and it has been actually heating my hot tub - went up to 112 degrees the other day - way to hot so had to turn it off. But it works incredibly well for both the pool and the hot tub.

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MonteK1
MonteK1

Reply 1 year ago

hello, I read your post- I also did this and painted my wood black and also put plexiglass over it- but I do not think it really increased the temperature that much. How long do you run your project? I live in NY and we have limited sun and heat depending on the day etc. I also have one end of the PVCD hooked up to my sump pump which sits IN the pool and that is taken out of the pool goes through the pool heater and then through a straight length of tubing that empties back into pool on the OTHER side. Any other ideas for me. I thought I did everything pretty dencent. I also used black zip ties. What I think I did is maybe coiled the tubing too close and tight? But I think this spring I will make another one and daisy-chain them together so that I get more water traveling through the PVC to hopefully get hotter.

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MonteK1
MonteK1

Question 1 year ago

Hello, I also made this last year and it came out pretty decent as well. But what I did- is I hooked up one end to a sump pump apparatus and the other end I draped around the other side of the pool. So the heat traveled from the sump pump pulling the cool water from the pool and then around the homemade pool heater and then through another straight length of PVC tubing to the other end of the pool where it empties into the pool. I also put plexiglass over the pool heater wood-- But I am not sure how really well it works-- I never let it run that long- but I really was hoping for a bigger increase in temperature--- I am thinking of making another one- and daisy chaining them together so that there wil be more pvc black tubing to go through to make it even hotter.?

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pixelmelter
pixelmelter

5 years ago

Why didn't you paint the board BLACK too? Or at least go back after this and hit the whole thing with black "trunk paint" (or maybe flat BBQ grill/fireplace paint) — make it big and black.

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CraigA56
CraigA56

6 years ago

This looks great.Do you have idea to get water to pool.

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Yonatan24
Yonatan24

7 years ago

Nice! Where I live, ~90% of the people use this to heat up water for shower/bath, It saves A TON of electricity

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karell.stemarie
karell.stemarie

7 years ago

would love to know how you hooked it up to the pool

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cfra2701
cfra2701

7 years ago on Introduction

That's a great idea I also built years ago. I just painted the plywood with black paint to keep the warmth. And I then added (because I found it in a trashbin near a diy shop) a plexiglass pannel over it. I used the spacer to make a well closed "box" which works as a heat concentrator. If I could have done it, I'd have put the whole assembly on my cabin roof at 45°.

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Elio23
Elio23

7 years ago on Introduction

I want to say thank you to you and other great insctructable who make me
very happy. See my photo. Thank you so much, Elio from Italy

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mbecks
mbecks

7 years ago

Do you have any idea how much this costs electrically speaking Vs just using an electric submersible heater? I get it was an experiment, I love a project like this, I was just curious if it's cheaper or more expensive in the long run.

0
neo71665
neo71665

7 years ago on Introduction

I know this was a 1 hour project but painting the plywood black helps heat it up a bit better. Also watch using white zip ties outside, they are not UV stable and break down faster than black ones.