Warming a garden pool - ideas?

[Peter Scott]

I've just put an inflatable pool in my garden. Tap water is rather cool but there's too much of it to think about warming it using hot water from the house. Nor do I want to wait for it to warm naturally. It's about 2.5 m across.

I can't see why I couldn't make a black panel of some sort to capture the sun's heat and warm the water, rather like a solar heating panel on a roof. Question is what to make it from?

I thought of making a grid of 15mm copper pipes and elbow and T joints, perhaps flattening the pipes a bit with a soft hammer. The trouble is the gaps would be large and heat wasted, even if I put a black board behind. Then I thought of an old radiator painted matt black. The water should flow by convection, but if it doesn't I can use the output from the motorised filter that came with the pool.

Has anyone else tried this and/or got some good ideas?

Peter Scott

[John Rumm]

A couple of layers of bubble wrap cut to the shape of the pool floated on the top when not in use would be a good start. Spray paint one layer black.

That will capture some solar radiation, while at the same time preventing so much loss due to convection. Might also keep some leaves out.

[mrcheerful]

A friend in Southampton does this with a home built panel, the sun face is old Perspex twin wall, the tubing is ten millimetre copper tube with very few joins in an across wise pattern, I can't remember what the backing is, but anything should do with silver paper on it to stop the heat warming the back too much, personally I would use a sheet of cellotex, he uses a central heating pump to circulate it all, the panel is about 6 foot by three and faces southish. it makes a lot of difference, likewise cover the pool at night with an insulating blanket of bubble wrap

mrcheerful

[The Wanderer]

How about some black hose pipe coiled to and fro, using water circulated from the filter?

[Will]

=09I tried something similar on one of the recent hot days, as a=20 quick rough and ready feasability study, to see if I could install a=20 diy solar water heating system that stood some chance of being=20 effective.

=09I found an old radiator in the shed, about 550mm x 800mm at a=20 guess, and sprayed it matt black. I fitted a couple of 10mm rad valves=20

- one to top of rad other to the bottom - pushed normal garden hosepipe=20 onto the valves, connected the hosepipe ends to a small tank, filled it=20 with water and waited for the results...

=09I think that it took about 4.5 hours to raise about 14 gallons of=20 water from 12 odd =B0C to 39=B0C.

=09Having read up on the subject in some depth, it appears that with=20 an airtight insulated box containing the radiator the front being=20 double glazed and the length extended to be longer than the radiator -=20 the extra length of said box being built such that the excess "ends"=20 are returned at an angle to catch more hours of sun - then the=20 efficiency of the panel should rise to the point of being viable.

=09So, as was already mentioned, if the pool is covered with a=20 thermal blanket whilst not in use, solar heating should be moderately=20 effective, at least.

=09Of course, if you utilise the filtration pump to force water=20 through a long length of black pipe laying in the sun, then the=20 insulation of the "collector element" is not needed, as the volume of=20 water passing through the pipe will ensure that only a modest rise in=20 temperature of the water will occur, so that losses back to the=20 atmosphere would be minimal.

=09Hope this proves to be of interest...

--=20 Regards,

Will.

[Dave Liquorice]

You haven't googled in here have you? This was mentioned about 2 or 3 weeks ago and last year. I should think "pool solar heating" should find the relvant threads.

[s--p--o--n--i--x]

I would also ensure that the inlet is at the bottom of the rad and the outlet at the top. That way you'd be drawing off water at the maximum temperature.

sponix

[Chris McBrien]

Talking of Bubble Wrap.....

I hate to admit this but sometimes I do the washing-up.

We have a double sink. One contains the hot water plus the Fairy Liquid and the other contains just hot water for rinsing the dishes. I've noticed and insulating effect with the sink containing the bubbles from the Fairy Liquid. This sink remains noticeably warmer than the sink with plain hot water in it.

This effect might make the paddling pool a bit more fun for the kids.

Chris.

x-- 100 Proof News -

30+ Days Binary Retention with High Completion x-- Access to over 1.9 Terabytes per Day - $8.95/Month x-- UNLIMITED DOWNLOAD

[Tony Williams]

I visited a place that made expanded polystyrene. Big tanks full of very hot water. They reduced evaporation loss by covering the surface with ping pong balls.

[Owain]

A man needs a clean tea-mug / beer-glass occasionally.

This is interesting as one would think the sudsy water would get cooler quickly; presumably this is the sink into which the room-temp dishes go first, which would have a cooling effect on the water.

An aerator with a small (solar?) pump should help produce lots of bubbles.

Owain

[Richard Polhill]

"Chris McBrien" wrote in news: [e-mail]:

Save bathing them later, too. ;-)

[Chris McBrien]

How about those building bricks with about 8 holes in them. They look about

15mm. in diameter and just waiting for a piece of Copper pipe. You could make an angled frame to hold the bricks so that it points to the Sun. Don't bother cementing them together just slide the Copper tube down the holes. Could spray bricks black or maybe they come in that colour.

No Patents Pending.

Chris.

x-- 100 Proof News -

30+ Days Binary Retention with High Completion x-- Access to over 1.9 Terabytes per Day - $8.95/Month x-- UNLIMITED DOWNLOAD

[graham]

I'd be surprised if that raised the temperature by much.

My parents used to have a proper inbuilt swimming pool in the garden.

We looked at heating options. To get the pool to a reasonable temperature using a proper electrical pool heater would take a couple of weeks. I think the electricity cost (and this was back in the

1970s) was going to cost about £300 - £400 per year. The pool heater would only be on for a few months in the summer.

Graham

[Harry Bloomfield]

mrcheerful . expressed precisely :

2" thick polystyrene [1] sheet is quite cheap and would provide a much better level of insulation and it would float on the surface. [1] The extremely light, white plastic, as often used for packing of delicate items.

[Peter Scott]

Lots of great ideas. Thanks. There is a cover but once it's warmer I like the idea of bubble wrap. The data about temperature rise was very useful. I'm going to discuss with my engineer brained son and decide which approach to use. I'll let the group know if we come up with anything that extends the above ideas.

Peter Scott