Why can we not have an immersion heater?

[WJT]

We have asked our plumber that is currently doing a lot of work at our house for an immersion heater. We have a huge old inefficient boiler that uses oil from a large 3000 litre plus tank that is used to heat our large water tank in the cellar. We have to turn each radiator valve off but leave the system on in the summer to heat the water. He has told me it is not possible to fit an immersion heater in our water tank. He has just now sent me an e-mail with a devis to fit a separate electric water tank for 1524 euros that we would use in the summer months to save on oil.

He can't seem to explain to me why he can't fit an immersion heater in our tank. Has anyone here experienced this or know this to be true? As always, thank you in advance for any information or advice.

[Higgy]

We had to have a new one fitted and it cost us about £200 but this was in 2002 it is about 5'6'' tall, I think it may

be 2000 litres but do not quote me on that.  We have hot and I mean hot water all day as the unit comes on at 10:30 pm

and goes off at around 4:30 am using cheaper electricity.  It is set on very hot but can be turned down, hope this helps. It

is housed in a small cellar area and is well lagged. 

[andyh4]

Could be true.

Heating water from an oil fire is normally with a seconday coil in the water tank.  The hot water flows from the boiler through the coil and heats the water in the water tank.  Fitting an immersion heater would require would require a second and different openning to place the electric heater.  If your tank was never fitted with this openning it will not be possible to just cut one and pop a heater in.

Alternatively or additionally, if your current tank is as old as the boiler, the tank may need to be replaced anyway.  However 1500 euros does sound a lot to install a tank that you can buy in the brico sheds for a couple of hundred - unless there is something very special about the tank - shape or size.

[The Riff-Raff Element]

That does sound high...I think I'd seek a second opinion.

It seems no matter how long we are in France, or how well we speek the language, there is always someone willing to chance their arm with a special "prix Britannique." The latest was a pair of herberts who claimed to be specialists in fitting solar water heating that my wife picked up handing out flyers by the checkouts in LeClerc. They gave us a devis for almost 12000 euros for fitting a kit we knew to cost off the shelf about 4500.

They included in the quote 100 hours of labour at 30 euros per hour and several hundred meters of copper pipe that they shouldn't need. Assuming, I presume, that we would be unable to read it and even if we could we'd be too minted to care. Oh and there was no way that the solar system could be integrated with water heating from a woodburner. Prats.

Happily we discovered that the plumber in the village - who has done all the work in our house and business over the past 5 years - had had some of his chaps trained to fit solar and he dropped off his quote yesterday. €5100, including a €600 grant from the Region and fitting only taking 30 hours...

[Poolguy]

[quote user="The Riff-Raff Element"]That does sound high...I think I'd seek a second opinion.

It seems no matter how long we are in France, or how well we speek the language, there is always someone willing to chance their arm with a special "prix Britannique." The latest was a pair of herberts who claimed to be specialists in fitting solar water heating that my wife picked up handing out flyers by the checkouts in LeClerc. They gave us a devis for almost 12000 euros for fitting a kit we knew to cost off the shelf about 4500.

They included in the quote 100 hours of labour at 30 euros per hour and several hundred meters of copper pipe that they shouldn't need. Assuming, I presume, that we would be unable to read it and even if we could we'd be too minted to care. Oh and there was no way that the solar system could be integrated with water heating from a woodburner. Prats.

Happily we discovered that the plumber in the village - who has done all the work in our house and business over the past 5 years - had had some of his chaps trained to fit solar and he dropped off his quote yesterday. €5100, including a €600 grant from the Region and fitting only taking 30 hours...

[/quote]

WJT

If you've got some out-dated equiptment its a great time to upgrade rather than try to press that old banger back into service with a 'gerry-rigged fix-it-up'. Certinaly oil fired heating is a 'dead duck' with oil prices rising 100% in the last 2.5 years and show no sign of slowing down.

As Riff Raff said; the new business is Solar- particularly evacuate tube solar, as it generated more heat per Euro invested that than any other technology. I read with satisfaction the Blog page from Riff raff who seems to have the 'bit between the teeth' to change from oil to Solar and wood burning, which is a great combination. However, I should point out with respect to the credit from the Impot that it is ONLY the cost of the COLLECTOR (that is; the actual renewable energy equipment) and NOT the whole system, nor the installtion which attracts the credit. We have had this view verified by three different sources within the Tax department Central office and now its in writting. So its not such a windfall as many promoters have been touting, but certinaly that does not in anyway detract from the reasons to change to renewable energy systems which are sound enough without reliance on aid and grants.

If you need more information on this its available on my website.

Andrew

[Gluestick]

If you really want one, then you can install a DHW (Domestic Hot Water) tank which is what is called "Bi-Fuel".

This has a standard calorifier (which is simply a heating coil) which imparts heat to the tank water from the central heating boiler (if your boiler is suitable to supply both DHW and CH) and also an electric element identical to a standard Ballon.

That said, you will find in practice that heating DHW from cheap rate electricity with a dual-tariff heueres Creuse-Heures Plein meter at night (nominally between 12.00 midnight and 08.00AM- this varies region to region) is far cheaper than burning oil.

And before you think "But the oil is free! I'm burning it anyway!", any extra heat taken from the system to heat the water compromises the CH: which will then run longer to reach the desired room temp.

Standard Ballons as already stated cost between € 200-400 to buy (200 Litre). Plus the cost of changing the meter and the additional cost of wiring, which also needs a pulse switch (Night-Day Switch).

Unless there is some structural reason which we cannot know, then your devis sound expensive.

Seek an alternative quotation.

 

[The Riff-Raff Element]

Andrew makes a very good point - only the kit strictly required for the solar part would attract the rebate. So, for example, a back-up electric heater to a solar circuit would be excluded from the scheme, even though some might argue that it is an entirely necessary bit. And labour most certainly is not rebated. A competent artisan should break out all the relevent bits on the devis.

You could consider a solar / electric combination. I've been very impressed by those I've seen in operation.

[WJT]

Thank you for all of the replies. I am disappointed that our current plumber came in with what appears to be such an uncompetitive price. His original prices for the work he is currently doing was very competitive but it appears that for anything else we have asked him to do has been very high. So it looks like for any future work we have to find another plumber.

We do hate having to use expensive oil in the summer and that was the reason behind wanting to have an alternative. I agree with the comment about using an old system but having enquired about replacing the current one, it at least on the surface appears that it would take many many years before we could see any savings. I have enquired about geothermal heating but because we have iron rads, I don't think it would be viable.

I would be interested to learn more about the solar system Andrew has mentioned and the costs involved. Unfortunately, it is not possible to change from radiators to underfloor heating. One of the jobs the plumber has been involved in is laying pipes underfloor for rads, including new ones as well as channelling and replacing old ones. Therefore, I don't know if we have any better options over oil at the moment but would be most interested to hear if that is not the case.

[Gluestick]

I looked at all the options: and still keep looking!

Underfloor heating using solar, geothermal whatever is fine: for new builds and barn conversions, e.g.

Not fine for existing old properties where excellent insulation is difficult (if not impossible) and retro-installing UFH would mean ripping up all floors and relaying plus re-tiling.

Then add the capital cost of alternative heating systems, none of which are cheap!

The best sort of midway step is using wood: best option is pellet fuel. Fine if you have the space to store the fuel in dry conditions.

Changing to a wood-fired boiler for CH and a cheap rate ballon is probably the best option for older properties in terms of the environment (wood is a sustainable fuel source) and running cost.

Looking at my nearby neighbour's new house, as he was installing the insulation and dry cladding, the methodology of construction, materials used and the care taken to minimise heat loss is impressive. Ideal candidate for New Wave green technology.

200 year old farmhouses aren't!

Sadly.

 

[Michael]

WJT.  Hot water cylinders can be fitted with Immersion heaters by installing a Essex Type Cylinder Flange.Br/Euro standard EN 60335.27.3 Your Plumber probably thinks its to old to mess about with and its prob scaled up anyway.Michael.

[WJT]

[quote user="Gluestick"]

I looked at all the options: and still keep looking!

Underfloor heating using solar, geothermal whatever is fine: for new builds and barn conversions, e.g.

Not fine for existing old properties where excellent insulation is difficult (if not impossible) and retro-installing UFH would mean ripping up all floors and relaying plus re-tiling.

Then add the capital cost of alternative heating systems, none of which are cheap!

The best sort of midway step is using wood: best option is pellet fuel. Fine if you have the space to store the fuel in dry conditions.

Changing to a wood-fired boiler for CH and a cheap rate ballon is probably the best option for older properties in terms of the environment (wood is a sustainable fuel source) and running cost.

Looking at my nearby neighbour's new house, as he was installing the insulation and dry cladding, the methodology of construction, materials used and the care taken to minimise heat loss is impressive. Ideal candidate for New Wave green technology.

200 year old farmhouses aren't!

Sadly.

 

[/quote]

 

Gluestick, that is not very good news but sadly had an idea that was the case. Our old boiler is actually dual fuel but we haven't used wood in it even though the previous owner apparently used it frequently. We have been told that it probably wouldn't be a good idea.

Let us know in your continuing search if you find the solution.[:D]

[WJT]

[quote user="Michael"]

WJT.  Hot water cylinders can be fitted with Immersion heaters by installing a Essex Type Cylinder Flange.Br/Euro standard EN 60335.27.3 Your Plumber probably thinks its to old to mess about with and its prob scaled up anyway.Michael.

[/quote]

Thank you Michael, you are probably right. I am beginning to think our plumber is running out of steam anyway.

[Poolguy]

As I said previously, I am adding a solar array to feed my domestic hot water needs (400 lt) and a bulk storage of 2200lt to feed the rads in my 260m2 house.

It will work fine for about 10or 11 months of the year but will need help for the last month so that the backup system (gas) does little or no work.

The details are on my website under the products section.

 

Andrew

[WJT]

[quote user="Poolguy"]

As I said previously, I am adding a solar array to feed my domestic hot water needs (400 lt) and a bulk storage of 2200lt to feed the rads in my 260m2 house.

It will work fine for about 10or 11 months of the year but will need help for the last month so that the backup system (gas) does little or no work.

The details are on my website under the products section.

 

Andrew

[/quote]

Hi Andrew, it sounds very interesting, I just had a look at your website. I assume I was looking at the correct section. Does this system need to have panels on the roof or can you have them elsewhere or is this system using a bore hole?

[Gluestick]

Andrew:

For how many hours will the bulk storage reservoir provide heat for your house.

What ambient temp. are you operating for rooms; e.g. lounge 22 Deg; etc.

How much insulation have you and how is this achieved?

Is the house an older property or newer and thus more thermally efficient?

Finally, what is the absolute extraction value in BTUs ( or e.g. Kw etc) per hour you can take from the heatstore and what is the duration, please, expressed in terms of xBTU's/hour?

Last time I evaluated the heatstore approach it was rather like the old electric storage heaters!

Had these in the UK in the early 70s on a White Meter tariff. Fine in the morning, but by 3.00PM it was becoming far too cold!

I do appreciate that the core problem with any form of alternative heating has always been energy storage and am thus keen to learn how far this has progressed.

I am thinking, for example wet rads drawing from heatstore, using cheap rate electricity as the prime source of heat, since Northern France is quite cold in Winter and extremely wet and cloudy most days!

Solar could provide DHW in the mid-Spring to early Autumn, but late Autumn through to late March it can be pretty dire!

 

[Chancer]

He is not being unreasonable with his price.

Whilst you can buy electric only ballon d'eau chauds for 200 euros, one with a seperate water to water element for your existing boiler (no matter oil or gas) will cost a kings ransom by comparison.

If you want to do it cheaply you will have to compromise, either have hot water from electricity only all year round or fit a second electric ballon assuming you have the space, both of these options would use a standard electric BDC.

I am sure that your chauffaiste will be pleased to give you a devi if you explain exacctly what it is that you require.

His price is quite reasonable when you consider that in the UK my friend who runs a plumbers merchants sells the same dual element high pressure cylinder for over £800 plus vat trade.

[Caussenarde]

Some more queries for Andrew;

Firstly I am very interested in installing a solar collector as one source of supply for a new CH and DHW system, chez nous.

For that reason I am very interested in the metrics which Gluey has requested, so hope you can supply the necessary.

Plus two other queries:

1. Hailstorms;  it is very common for very intense summer storms to produce golf ball calibre grellons hereabouts, easily capable of denting cars and breaking roof tiles.

Can you give some guidance on the hail hardiness of the evacuated tubes pls Andrew ?  I have seen some tubes, similar to those you supply, in Leroy Merlin and I immediately thought of the risks of hailstorms.  If the tubes were covered by my insurer, maybe Ok but I am not sure they would be ? 

2. Plus, what have you used for your 2000l heatstore ? 

Hope you can help, best regards

[bejay]

1. Hailstorms;  it is very common for very intense summer storms to produce golf ball calibre grellons hereabouts, easily capable of denting cars and breaking roof tiles.

Caussenarde

I know you are correct about the size of hailstones My car has the dents to prove it, The only person I know who has fitted evacuated tubes was told by the fitter that the only thing they wouldn't stand is being struck by golf balls.

HTH

bj

[Poolguy]

Caussenarde/ Gluestick

Thanks for the specific questions

First ...hail! (Ave!)

The tubes will resist an impact of a hail stone up to about 20 mm, over that you might get one or two broken - nevertheless the system will keep working, albeit less. What ever happens its only the glass tube which has suffered and can easily replace the broken tube or two or three at about 20 euro each. The whole system has not been compromised, as it would be a flat plate collector.

Heat output is another question as it depends on a lot of variables not the least of which is where in France you are situated. But taking Southern France for example one 58mm tube will produce about 1.05 kw under full sun. A 47mm tube in the same place is about 0.7 of a kw (sorry I have no idea what that is in BTU). To take an average though is best to cut it in half for calculation.

So I am using 120 tubes to do the work in my house which amounts to about 20m2 of collectors- or 120kw ideal (60kw average). I cannot tell you till the system is commission what the yield temps will be. During days like these I expect it to be tremendous as one tube will boil is contents of water in about 40 mins, and its still winter.

The Temp storage is ceramic-coated galv, steel cylinder for storage 2200lt and a 400 lt twin coil for HW. How many rads that will drive at what temp is another days maths, I'm using the 'rule of thumb' from the people who have had the experience with heating systems, and we'll see how it goes. If the whole system lacks grunt for my latitude then I can add another panel or more storage as I want. The hard stuff is already done and I would just be getting the system 'tweecked' to suit me - vis paying the least in gas bills.

The tubes in Leroy Merlin are typically a cheaper version and there are a few about but I am happy to stay will Navitron for their innovation in Stagnation and heat overload technology, is where I am putting my trust. That means, its fine to get huge grunt out of the system when its cold and wet and nasty, but when its hot as can be in summer where does all of that 120kw of heat go....? You don't want it in the house, .. or the pool.

So, apologies to all those people using Mozilla search as it seems that my website appears to be tiny. If you can use Internet explorer from Microsoft then its full size. (I don't know why... sorry, I have to consult the web guy)

Andrew

 

[Gluestick]

Many thanks for reverting on these questions, Andrew.

Will you please keep the forum updated on how well your system performs?

I know that quite a number are looking at various alternative forms of heating, as gas and oil have zoomed in price.

When we first purchased our house, heating oil was circa 33 cents/Litre.

A tad more now!

[Www]

[BIG MAC]

Plumber was reasonable for everything else?...I am a plumber by trade and I think that rather than trying to fleece you he may missunderstand what you are asking for. I would ask him for a schedule detailing all he will do for the money maybe there are norme compliance issues that we don't know about. Ie maybe he would be required to change the tank or install a pressure vessel...If the guy is fair and honest elsewhere and you have a good relationship I would talk to him first..maybe he has miscalculated even. My glass is half full on this one at the mo...Bon chance

[Caussenarde]

Ave Andrew,

many thanks for taking the time to give your reply.

A couple of questions arise

Do you really mean 2200 litres  (ie contents of 2.2 tonnes?) steel cylinder ..what did it cost approx I wonder ?

I still haven't got to your site yet so apologies if this is covered there:  So, what are you going do you do with 120kW overheat in mid-summer? or how do you avoid it collecting it?  I have looked at the Navitron site (also problems with screen size!) and using their estmates I get your store to have a capacity of approx 100 -120 kWh, so on a 'bad' day in August you might be dumping heat for most of the day...plus what to do with the 100kWh storage when it is 30 degrees outside at night ?  They talk about steam ...not good !! Running hot water to the drain is also not very enticing.

I guess these three points are the key problems or stop-points for me, with respect integration of solar into new CH system ie, hail damage (already covered), heat store capacity and overheat.  I can see a small capacity array for DHW would work, but for CH, I do not see how to harvest enough energy in winter without severe problems in July/August.

Am I missing something? hope so because, en principe, it is an excellent solution for me.

cheers

[Gluestick]

How about using the heat to air condition the house?

Using Absorbtion Refrigeration rather than a compressor, the unnwated solar energy is translated into chilled air.

Furthermore, this technology (invented back in 1922!) uses no environmentally "nasty" gases.

By the addition of a simple Photo-Voltaic array to power the fans, it's a Win-Win-Win solution!

http://www.rotartica.com/pub/ingl/index.html

It struck me over 30 years ago, in Southern Spain, when I was involved in modular system building projects to the Third World that the dichotomy of wanting coldness when the sun was at its highest meant that by combining solar energy with absorbtion refrigeration, one was using free energy to overcome its negative effects on buildings!

Cheaper older domestic fridges, of course, used the absorbtion technology, those powered by gas and electricity were common in caravans, as were those powered by paraffin/kerosene.

Instead of using a compressor to reduce gas volume, the absorbtion fridge uses heat to expand the refrigerant: which is then cooled in the evaporator tray.

 

[Poolguy]

Well that is truely fascinating Gluestick and aa big thanks.

I have sent of a contact to them the get more information and will let you all know how I get on as, I was going to vent excess heat from my panels to the air, but now we have not only somewhere to put it but gaining some coolth at the same time.

This just gets better and better, (and its about to get so good that we might even save the planet in the process. Its new photovoltaic technology, which will make electricity generation on large scale viable using the sun.)

But for the time being I glad to distribute this great solar thermal technology to anyone who wants to spend less and be greener.

To answer the other question, I really meant 2200lt storage, over 2 tonnes of water and the cylinder is avaialbe with or without back up electric coil. In my case I choose without as my secondary system is gas so the list price is 2295euroTTC

Viva la forum.....!

 

Andrew

sola virtuous nobilitat

[Caussenarde]

But back in the real world...the here and now...

what about overheat...where does 120Kw actually go chez vous when it is 38C outside...

If I could just figure that out then solar for CH is a goer...sinon..

PS we already have climatisation.