Heat your pool to extend its use by many more months in the year. While there are many ways to heat your pool, one of the most economical and environmentally-friendly solutions is totally free and clean. You might even say it’s a gift from the sky: solar energy!
And the good news is you can make your own solar water heater using basic materials that are easy to find and won’t cost you an arm and a leg.
What you’ll need to make your DIY water heater and heat your pool
- a 1 x 1m wood panel (here, two water-resistant OSB panels were assembled, but you can use other materials or recycle pallet wood for the back of your solar water heater)
- hose measuring 50m (here we used a red 16mm PER hose, which limits dilation when the water is hot but you can also use 16mm non-porous PE irrigation hose )
- two elbow connectors that will fit your hose (not necessary if you’re using a PE hose)
- two connectors to connect your solar water heater to your pool hose
- black matte exterior paint (here we used spray paint)
- eight eyelets with a 10mm head
- four 10mm rounded beechwood dowels, 60 cm long (you can also use pvc pipes)
- four treated timber battens measuring 60 x 40: two measuring 1m and two measuring 0.92m
- one polycarbonate sheet measuring 1 x 1m for your solar panel
- 70mm and 40mm stainless steel screws and washers
- two 45° mounting brackets two battens for the legs
Making your DIY solar water heater
Step 1: Prepare your wood panel
Draw diagonal lines on the side that will become the solar panel. Use a pencil to mark 23 cm from the corners and 23 cm from the centre. Screw in the eyelets at these points. Pass the beechwood dowels through the eyelets. These dowels will allow you to keep the hose in place as you roll it up.
Step 2: Roll the hose up
Roll the hose up in a round circle, keeping a margin of approximately 1m wide at the ends. Make sure to roll it up flat as the hose must fit under the wooden dowels. Start by rolling from the centre, without forcing it too much to bend. Remove the dowels from the eye bolts to make room to position the hose and then slide them back into place, once you’ve finished.
Continue this way until you’ve reached the end of the hose; make sure you still have 1 metre of the hose free for the connectors.
Tip: You might need an extra pair of hands, so ask someone to help you with this step if necessary. We also used a bit of tape to hold the margin in place (see above photo).
Step 3: Finishing the back panel
Attach the wood battens all around the frame using stainless steel screws. Using the hole saw, drill two holes into one of the corners so you can pass the hose through without bending them. Use the elbow connectors to prevent the hose from being pinched or crushed.
Step 4: Paint everything inside the frame black for optimal heat absorption
Add a layer of matte black paint to the inside of the frame. Make sure to cover the hose, wood, dowels and anything located inside the panel. This will make sure it absorbs the heat more effectively.
Step 5: Cover your panel for even more heat
Attach the polycarbonate sheet to the frame using stainless steel screws and washers. This material will create a “greenhouse effect” inside the box. It will also protect your heater from wind that could cool the water down.
Step 6: Tilt your solar panel to maximise the sun’s energy
On the back of your solar panel water heater, attach the legs using the mounting brackets.
Use fittings so you can connect your hose to the pool pump. You can either choose to connect your water heater to the pool pump – if it’s powerful enough – or have your heating system run alongside the pump in a parallel circuit to heat your pool.
Once your water heater is set up, water will come out between 28 and 40°C, depending on the weather and how you’ve positioned your panel. We tested the device at the end of June in direct sunlight. While the outside temperature was 23°C, the water coming out of the panel hit 32°C!
Did you enjoy this article on how to heat your pool with this DIY solar water heater? Here are a few more articles you can enjoy, such as how to build a swimming pool for less than £100, or our guide on pool cleaning products, or even our inflatable pool buying guide!