bil8999

Hi
Thinking of heating pool 8x4m.
Any thoughts on either solar, heat exchanger or pellet burner.
Installation cost, running costs, long term problems etc.
We are only using the property about 12 weeks of the year but would like the water temp up a few degrees.
We do have a pool cover which helps.

Thanks in advance.

amideislas

There is a one low cost and effective way to solar heat a pool, but it requires a little space. We learned this from a local, we use this method and it works quite well.

Get 200 meters of black PVC irrigation tubing. We use 40mm. Should cost about €100 or less.

Find a spot somewhere away from the pool area where there is full sun, and lay the tubing down in a tight coil. Do it in the sun, because the tubing becomes much more flexible when it's hot. You'll probably need a circle of about 8-10 mtrs to accommodate the entire length of the tube.

The most tidy and least visible method is to run a line from both ends of the coil to the existing pool pump, and insert it between the feed from the pump and the feed to the pool, adding a valve that bypasses the coil. Adjust the valve to direct some or all of the output of the pool pump through the solar coil, depending on how warm you want the pool.

Optionally (easier, but more visible) is to get a small submersible pump. Those pumps that are used to drain flooded basements work well and cost about €30. Just attach the entrance to the coil to the submersible pump and drop it into the deep end of the pool (yes, it's the easy way). Drop the return line from the coil into the shallow end. Add a timer to the submersible pump that turns on the pump every 30-40 minutes for about 10 minutes or so, from say, 10:00 to about 18:00 (in summer). When it's working, you'll feel hot water coming out of the coil return. Depending on the size of your pool, within about a week you'll find your pool will be much much warmer.

We originally put our coil on the ground, but then we built a little pavilion with a black PVC roof at the pool with a bar underneath it, and later moved the coil up to the roof of the pavilion, and buried the feed and return lines to the pool, which works even better, and is a lot less visible.

One drawback is that a warm pool encourages more algae, so you need to use more chem. But the benefits are both a warmer pool, and a longer season of comfortable use. A 30c+ pool is especially great at midnight.

EDIT: We also bought one of those €5 digital thermometers that show both indoor and outdoor temperature. The outdoor temperature sensor is on a short cable that you're supposed to run to the outside. But I took it to the pool, attached a longer cable to the outdoor sensor and dropped the outdoor sensor into the pool, and hung the thermometer at the bar. Now it shows the air temp ("inside") and pool temp ("outside").

BlackBeardie

Oh very well done! I want to try this later on when I eventually get round to building a pool. Iºm going for a natural pool though so there will be algae and ...frogs ._.

EMR

I have looked at using the black tube method on the roof but the problem to overcome will be getting a small pump with sufficient pressure to take water from pool to pipe.

crookesey

The villa we use in La Fustera has one of those large cylindrical units with a fan on the top. This is actually an electrical pool heater/heat exchanger, unfortunately when it was installed it was placed in permanent shade and is very expensive to run. I just wondered how much more economical these are if placed somewhere where they get the sun on them.

Domino

have a look at AKI they have a reasonable range
otherwise the likes of Brico and perhaps Leroy Merlin

hth

bil8999

Thanks for help so far.

Any more thoughts regarding heat pumps or solar panels.

Thanks

snikpoh

We have a system which uses solar power - not to produce electricity but to heat the water.

The hot water is controlled by a control unit which regulates when to pump and when not - it is continually measuring the difference between the pool temp and the panel water temperature. The pump itself is just another pool pump.

By regulating the max and min temperatures one can control how long this system is on for each day.

By using this system and the usual winter and summer covers we have been able to extend the use of the pool to between April and October - not much longer perhaps but fine for us.

In the summer we turn the panels off as the pool gets up to 30-32 anyway.

amideislas

Well, OK... just get one of those little propane/butane hot water boilers that heat the water as it passes through it. Either add a small pump with a timer to suck water out of the pool and push it through the boiler and return it to the pool, or connect the boiler between the output of your existing pool filter and the pool return.

In either case, pushing pool water through the boiler triggers it to start heating and it stops when the water flow stops. So it's probably better to use a separate small pump which you can put on a timer, or else your pool may end up more like a hot tub and cost you a fortune in gas.

You can buy the boilers cheap, I've seen second-hand ones for €50 or less. The only problem is that they have somewhat limited flow capacity, so if your insert it between your pool filter pump and the pool, it may reduce water flow.

If you want solar, the tube trick works very well, but if you want a "proper" solar panel, then most pool shops have them for about €200 for 2 sq. meters, which actually isn't much surface area. You'll probably need 2 of them at least.

MrsMac59

Hi all,

We've been chewing over how best to add heating to the pool at the house we're in the process of buying. At one of the houses we looked at earlier in the year the owners had an array of several small coils of what looked to be smaller diameter black piping than Amideislas has described, each arranged on a metal back plate and propped up at a good angle to catch the sun. These were on part of the plot beside the pool but cleverly shielded from view by the way the garden was laid out. We wouldn't have seen them at all had they not been pointed out to us. We very much like the idea of using the black piping so we'll probably be back to ask more questions about it later in the year but thanks for info already provided. Cheers!

EMR

We were told that you need a solar panels equal to 50% at least of the pool surface area.
But it all depends how warm you want your pool.
We get 28 degrees + in summer which is more than enough, it is in the spring and autumn that we would like to raise the temp.
Keeping a cover on at night can save you 2-3degrees of temp loss.