Building a DIY Solar Pool Heater

Steps

1. 1

   Step 1: Gathering the materials

   Watch this part (2:01)

   I gather all the materials needed to build the new solar heater panel. Having the right supplies ready makes the build much easier and keeps costs low.

   What I used

   Item	Amount	Notes
   Hardwood plywood sheet	1	9mm thick, 1.22m by 2.24m, moisture-resistant
   Wooden slats	3	27mm by 44mm, 2.70m long
   Black paint	1 pot	From Action, cheap and good quality
   Flexible PVC hose	100m	19mm thick

2. 2

   Step 2: Cutting the wooden slats to size

   Watch this part (2:38)

   I start by sawing the wooden slats to the correct dimensions for the frame. I need two lengths of 2.44m to match the plate length, and two width pieces based on the plate width minus the raised edges.

   What I used

   Item	Amount	Notes
   Wooden slats	3	2.70m long

3. 3

   Step 3: Assembling the wooden frame

   Watch this part (2:58)

   I screw the first side rail onto the plywood plate from the bottom up into the balk. I made a silly mistake here by calculating only one slat width instead of two, so I had to cut it again to 1.16.6m instead of 1.19.3m. After fixing this measurement, I finish screwing the wooden box together.

   Warning

   Remember to calculate the thickness of two slats instead of one when sizing your frame parts.

   What I used

   Item	Amount	Notes
   Screws	Several	Used from the bottom into the balk

4. 4

   Step 4: Spraying the wooden box black

   Watch this part (3:24)

   Once the wooden box is built, I give it a light coat of black paint so it is dark to begin with. This way I do not have to paint underneath the PVC pipes later on, which saves time. I use a cheap spray gun from Lidl and paint from Action, which gives great quality at a low cost.

   What I used

   Item	Amount	Notes
   Spray gun	1	Cheap model from Lidl
   Black paint	1 pot	From Action

5. 5

   Step 5: Unpacking and dividing the PVC hose

   Watch this part (4:10)

   I unpack the 100-meter roll of flexible PVC hose and divide it into four equal pieces of about 25 meters each. Splitting the water flow over four pipes instead of one reduces water resistance so the pump does not have to work as hard.

   What I used

   Item	Amount	Notes
   Flexible PVC hose	100m	Divided into four 25m pieces

6. 6

   Step 6: Laying out and securing the PVC pipes

   Watch this part (4:46)

   You can buy PVC clamps at the hardware store, but I printed mine and will put the design in the description. I place the first hose as far as possible against the edge, put a clip over it, and nail it down. I lay the next lines right next to each other, following the corners in a spiral until the whole box is filled.

   I also add an extra 20 meters of hose to make the panel longer and more effective.

   What I used

   Item	Amount	Notes
   PVC pipe clamps	Several	3D printed
   Flexible PVC hose	20m	Extra length added

7. 7

   Step 7: Connecting hose extensions with PVC glue

   Watch this part (6:16)

   I take an extra 5-meter piece of 19mm hose and attach it using PVC glue to ensure a water-tight connection that will not leak. I am generous with the glue because fixing a leak later is a big job.

   What I used

   Item	Amount	Notes
   Flexible PVC hose	5m	Extension piece
   PVC glue	1	For water-tight joints

8. 8

   Step 8: Installing copper water connections

   Watch this part (7:24)

   I use 12mm copper tubes glued to short pieces of garden hose, which provides a rubber seal that glues easily to PVC. I mark and drill 12mm holes in the frame, making sure not to hit the pipes underneath. I push the hoses through the holes to the back of the box and secure them with screws so they will not move when I attach external hoses later.

   What I used

   Item	Amount	Notes
   Copper tubes	Several	12mm diameter
   Garden hose	Short pieces	Glued to copper tubes
   Drill	1	With 12mm bit and spade bit

9. 9

   Step 9: Sealing with hot glue

   Watch this part (9:42)

   I apply hot glue over the pipes and in between them to seal the maker wind-tight. Hot glue is also known as hot snot, and it helps keep the heat trapped inside the box.

   What I used

   Item	Amount	Notes
   Hot glue	Several sticks	Used for wind-proofing

10. 10

    Step 10: Applying the second coat of paint

    Watch this part (10:05)

    I vacuum the box clean and use the spray gun with Action paint to apply a second coat of black high-gloss paint. The black color absorbs a lot of heat from the sun. I let it dry overnight.

    What I used

    Item	Amount	Notes
    Spray gun	1	Lidl spray gun
    Black high-gloss paint	1 pot	From Action

11. 11

    Step 11: Covering the panel with transparent foil

    Watch this part (11:02)

    The next day, I add a few blocks in the middle to prevent sagging and help water run off. I fold a transparent plastic sail over the solar heater and staple it to the bottom and sides. Sunlight passes through the plastic to heat the black pipes, while the plastic blocks cold wind from blowing the heat away.

    What I used

    Item	Amount	Notes
    Transparent plastic foil	1	Cover sheet
    Stapler	1	For securing the foil
    Blocks	Several	Placed in the middle to prevent sagging

12. 12

    Step 12: Hooking up the pump and splitter

    Watch this part (12:04)

    I place a 3,000 liter per hour submersible pump in the pool and run a green hose upward to a splitter that divides the water into four channels with separate valves. I secure the hoses to the PVC pipes using hose clamps and add pieces of electrical conduit around the ends to prevent the hoses from kinking.

    What I used

    Item	Amount	Notes
    Submersible pump	1	3,000 liters per hour capacity
    Green hose	1	Connects pump to splitter
    Splitter	1	Splits flow into four channels
    Hose clamps	Several	Secures connections
    Electrical conduit	Short pieces	Prevents hose kinking

13. 13

    Step 13: Takeaways

    • Dividing the water flow across four parallel hoses reduces water resistance and helps the pump.

    • Painting the wooden box and PVC pipes black maximizes solar heat absorption.

    • Covering the panel with transparent plastic lets sunlight in while blocking cold wind.

    • Adding electrical conduit prevents the flexible hoses from kinking near the connections.