Advice for heating and covering our pool please

Hi everyone,
We are very grateful for the information you have all given us so far,now we are unsure of the best way to proceed with our pool and would welcome any advice.
We live on the border of Landes and Pyrenees Atlantique and have an outdoor pool 11m x 5m (67m3). We want to use the pool from March to October hopefully and when we were viewing houses we saw one with a heat exchange pump and electric hard cover that the owner claimed they used for this period. We have also been given a brochure for Abritech covers and so our question is,would an Abritech cover heat the pool sufficiently ? and if we had a heat exchange pump what size would we need and how expensive would this be to run ?
We have not had quotes for either option because we don’t want to spend money on something that won’t deliver or that we can’t afford to run!

Hi Caryn,
Do you know if your pool has any insulation in the structure?
Any idea of the temperatures during the periods you wish to use your pool. As you quite rightly state a heat exchange pump, doesn’t make heat it transfers it thus if there is insufficient heat in the air you’ll be struggling to heat the pool.
Do you have mains gas or bottled?

Hi John and Caryn

Just throwing an idea in here… friends have a sliding armadillo cover (quite tall one actually), which means that even on a blowy/chilly day, they slide a piece open (opposite to the wind) and swim in the well protected pool.

They’ve obviously chosen the alignment of their pool with care and use it all year round. It is in full sun all day. It has no heating, but they are hardy French folk… :relaxed:

Hi John,
I’m not sure about insulation,it was built in 2003 and has a good liner.At the moment the water temp is 23.5C with no heater or cover and that with all the rain we’ve had this spring. I guess the air temp in March and October may be 15C. We have an Antagaz tank but use that for our Aga!

OK, the Abri will help a great deal as it prevents the loss due to evaporation and drafts which could loose you around 10KW as you are trying to heat. I was looking at tables for heat pumps, bigger is better with a heat pump and the inverter technology is far better from an efficiency point of view but obviously the cost rises. I would recommend an 18KW unit for your pool but you may also want to consider a gas boiler and heat exchanger as the capital cost could be a lot less and outside temperatures won’t have a drastic effect on the pool heating. One of my customers with a similar sized indoor pool has a 21KW single speed non inverter heat pump and that was struggling to raise the water temperature to comfortable with outdoor temp around 10-12C. As they are open all year we installed a 35kw gas boiler with over sized heat exchanger to give quicker heat up and that has proved perfect to the point I may consider doing the same.

Thank you John,we have someone coming tomorrow to give a quote for an abri. How do we know how expensive in electricity the heat exchange pump would be ?

I can only give you an idea and that is based on generalisation.
An 18kw heat pump with a COP of 6 would use 3kw of electricity per hour and with electricity being around 20 cents per kw it would cost around 60 cents per hour. that doesn’t guarantee a heat output of 18kw in colder air you may get 12kw so you would need to run for longer to gain the same heating.
Because full inverter heat pumps are far more efficient the COP can climb much higher than the old on/off single speed units but of course they cost more, hopefully as there is less strain on the moving parts they will last longer as well.

That’s why I mentioned the gas boiler and heat exchanger, probably cost 1/4 of the heat pump, will work no matter what the outside temp is and you get a lot of gas for the difference.
Hope that helps.

Hi John,
Thank you so much for your help.We’ve just had a quote in excess of 19,000 euros for an abri with motorisation. Still trying to do the maths,if the 18kw heat pump cost 60 cents per hour and we had it on for 10 hours a day for 8 months of the year, can we predict an electric bill no more than 1500 euros a year or are we way off course do you think?

This is something like the cover my pals had… I called it armadillo and now realize that Armadillo means other flat covers as well…

http://www.mip-swimming-pools-france.com/swimming-pool-Abris.html

(Further to John’s comment…)
Amendment: this link is simply to offer some ideas of what sorts of abris are available… I am not recommending MIP in any way whatsoever. I would advise anyone to to lots of research before settling on a particular provider.

cheers

Thank you for the link Stella and while you are here can I say thank you for your advice re our first french tax return. You said go and talk to them they are not ogres. We collected the forms,filled them in after researching as much as possible and despite entering the info in the wrong section,the official simply transfered the info onto the correct section et voila! we couldn’t believe it!

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I’m so glad it worked out OK… have you kept a copy, so you get it right next time… ??

Yes definitely!

I really don’t think you’ll need it for 8 months of the year, June July & August unless we have freak weather it would most likely be off or maybe on for 2-3 hours because of the air temp and the need to actually cool off in the pool. You may need it on for 10-12 hours or even a bit more during the colder months. Very tricky to predict, just like the weather, don’t be seduced by low cost models that are for warmer climates, go for one used in cooler climates.

Be careful recommending MIP there is a fair amount of sales BS on the site. Any company who sells Ecosmarte is more interested in their profit than your pool.

Hi John… I was not recommending any company just trying to show the sort of cover which our friends have on their pool.

It allows them to use the pool in inclement/windy weather and still enjoy the experience… a bit like swimming in a greenhouse… :wink:

this link gives more ideas of the abris available…

Hi John,
Thank you for your continued patience,we now think a heat exchange pump and a hard motorised pool cover would be our best option rather than an Abri.
Our local agent has a Zodiac 300 MD8 21 kW with a COP of 5.5 would this be for us please?
Also, can it stand unprotected like an AC unit or does it need a cover?

Hi John
Further to my message above,we have just returned from the pool shop and they have recommended a PAC M90 which is 18.2kW with a COP of 5.3. Have we been seduced by a heat exchange pump for warmer climes or is this OK ?

If it’s not too late, have you considered solar heating? We don’t have a pool, but I put a single solar panel of 20 evacuated tubes on our roof eleven years ago. It saves us 500 litres of fuel oil per year. The 500 litre tank that we have will often be full of hot water in the Summer with the middle of the tank around 55c.
I bought our system from Navitron in the UK. They also do systems for swimming pools.
[https://www.navitron.org.uk/]

Paul I like solar but on pools there are a couple of drawbacks. On average you’d need 3x the number you have so a bit of space required. Some way of dumping the excess hot water in summer when the pool is up to temperature. You could use it for hot water as well but you still have to dump the excess. One way could be to fit electric blinds to stop the sun getting to the tubes but linked to the thermostat so they open when required. The blinds would also protect the tubes in a hail storm if they were tight enough and sufficient gap provided.
More suitable for when permanently resident than part time