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Heating/HW advice needed..


Jules
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I've recently bought a 5-bed farm house with attached coach house near Cast in Finistere. Both in need of complete renovation. We will be converting the main house into Chambre d'Hote, (5 beds), with the coach house converted to 3 gites, (5 bed, 3 bed & 2 bed). Neither building has any CH or HW system.

I wasn't planning on fitting CH to the gites, so would a ballon be the best solution for HW? As for the main house, what would you recommend - I've been looking into air source pump for CH, can these also heat the HW sufficiently, or would it be best to include electric element as backup.

Any advice greatly appreciated...

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Twin coil mains cylinders on overnight tarrif for dhw (one to serve each letting unit - sounds excessive but means you only affect one unit at a time when working on them or if you get a 'water greedy occupant' backed up with solar as most of your custom will be in the decent weather. This method should also provide some benefits to the main house in the winter  if you install a thermal store so that any over production of heat energy gets caught and used when needs be.

For heating I would use air source in the gites as it can double as AC and you can advertise AC in the apartments as a benefit.

For the main house I would likely go to Underfloor on a Solar / solid fuel combination thereby using the log burner or boiler to further charge the thermal store andthe heating running from it even if you have to use rads it's probably a good controllable set up....your major obstacle will likely be the cost of insulating properly (absolutely vital) and then the cost of the equipment which at current values may cost in excess of £10k not including concrete works or flooring... however....Gas and oil is not likely to come down in price over a ten year period. Overnight electric is reasonably priced and probably nuclear so less reliant on fossil fuel. Solar is free other than maintenance and obsolesence.

If I win the lottery..the above would be what I would be installing!

 

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Air source would be too reliant on ambient temperature....in the winter it is going to struggle to pull heat out of -10 degrees so you could be gathered around the cheery glow of the electricity meter...

Solar and overnight electric ia thermal store would be more efficient in my opinion...

 

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Well mine does not struggle and I get about 3 to 3.5kw of heat for every 1kw I burn. The temp has been down to just over -17 and it's functioned without a problem and the meter does not whiz round at an amazing speed either. Had it for just over 2 years now although I bought a 'test' unit for one room before that and it's probably the best and cheapest heating method I know without without digging up the garden and the internal floors for a ground source heat pump with underfloor heating. You do need to go for inverter type systems though.

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good Morning Quillan

 

which brand are you using..

 

I will ( on friday )  have a huge room, of 75 sq m with tall ceilings,  !  the second room is around 55 sqm .. 

 

The whole property is around 400 sqm. The heating needs to be thought thru.. It already has oil central heating, intending to put in a couple of wood burners to assist .

 

 I do like the idea of heat exchange even if it  only takes the chill off the place.  Perhaps in winter on a frost stat , for when we are not there.. !  What really worries me is there is a tank in the roof space/loft, yes lagged, but as with all french houses the loft is ventilated and with the recent very low temperatures I am a little bothered..  any thoughts /bright ideas, or just euro notes to burn are welcome 

 

are frost stats common in france, or will the plumber give me a blank look  ?

 

sorry for the hijack

rgds

Bill

 

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I bought mine from Brico Depot, they are the inverter type. The difference between these and standard units is the pump varies in speed with inverter types where as the other type it's on or off. The economy is that you use more power to start the pump than you do if you simply vary the speed once you have reached operating temperature. I have given a link below.

http://www.bricodepot.fr/carcassonne/chauffage-production-deau-chaude/pompe-chaleur

Oil, gas and electric panel heaters all have the ability to use frost stats and yes they do use them in France and know what they are for.

What is the tank in the loft for? If its a header tank for the heating then providing you have the right mix of inhibitor/antifreeze you shouldn't have a problem.

The lowest temp I can set mine too is 16 deg on heat so I wouldn't recommend setting them at this temp and just leaving them to protect against frost. They are designed to be the main source of heating so you would use the CH system to supplement these units and not the other way round. After all the idea is to save money and that's what these units do, well compared to those flash electrical radiators we had. When you consider to replace a 2kw radiator of the same spec as we had would cost us around 400 Euros each and we have three in the lounge dinning area. Compare them to the one inverter unit (to do the job of the three other heaters) which costs 900 Euros yet the electricity consumption is reduced by 60% (or more) I think they are a good buy. I believe somebody said the cost of heating with gas, oil and electricity is about the same these days and electricity may become cheaper in the future.

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Fair point Quillan until you look at the size of the place and the ugliness (to my mind) of split air source kit in and on a main building. I dont know the relative areas however if you were to have 900€'s worth of kit to each renter x 5 plus the main house...then drawing about 5 to 6 kw to do it not to mention starting loads...I agree electric is really the only option and that to use it sparingly is sensible hence why I think solar is way to go....particularly in a guest house where hot water is a pre-requisite and is generally over produced or expensively produced 'instantly' ala combi boiler or plate heat exchangers.... Microwave water heating will be the future but not really viable just yet ...I think the Vulcara Mk4 is about as far as its got.

 

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I was under the impression that I and he were talking about the main house and not the Gites. If I am wrong then I apologise.

For the external unit you buy a 5M long pipe kit (pre gassed) which gives you quite a bit if distance to mount the unit where it's not so noticeable. If you want you can run your own pipes in if that's not quite long enough. You can also box them in (providing your follow some basic rules) and/or turn them in to a feature.

If the Gites are only being used in the late spring, summer and early autumn and don't really require heating then your right solar panels for hot water would be an excellent idea.

If your going to fit heating in to the Gites, especially if its electrical why not use a card switch. We now use these for the rooms and the electric gates. This means guests have to take the key with them to get out and so the heating or a/c is not left on in the room. We bought ours from these people http://www.diyses.co.uk/ as we couldn't source them in France although I am sure they are out there somewhere.

With regards to generating electricity by solar the technology is not there yet and several universities have done research on 'pay back' including such places as Cambridge (I gave a link to theirs ages ago and can't be bothered t find it again) and whilst they all agree to disagree in the actual length of time you are talking about between 50 and 80 years depending on who's report you want to use. Given that the panels, the major investment, degrade dramatically in performance after 25 years (which most suppliers appear to give as their life span) its like pushing £50 notes down the shower plughole with your big toe as fast as you can.

By far the best solution for heating is geothermal if your building or renovating from absolute scratch (i.e. replacing all the floors) and you have the garden to lay the outside pipes. To retrofit in a normal house is just too expensive, not in the cost of the kit but in laying the new floor, making good and decorating after.

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solar arrays !  

 

I'm  not sure if the french are subsidising, but many governments are...  seems to make a big difference, payback in this country is about ten years, disregarding inflation/deflation  of energy.

farmer up to road (UK)  has gone barmy and spent 60,000 on one array on his barn.. put up the barn specially.. he is anticipating even faster pay back as claims agaisnt tax , and gets his vat back as registered.. If the gites are a biz niz, then perhaps the vat /cost is claimable .

rgds

bill

 

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[quote user="Bill"]

solar arrays !  

I'm  not sure if the french are subsidising, but many governments are...  seems to make a big difference, payback in this country is about ten years, disregarding inflation/deflation  of energy.

farmer up to road (UK)  has gone barmy and spent 60,000 on one array on his barn.. put up the barn specially.. he is anticipating even faster pay back as claims agaisnt tax , and gets his vat back as registered.. If the gites are a biz niz, then perhaps the vat /cost is claimable .

rgds

bill

[/quote]

I don't know where you get that figure from but The Energy Saving Trust (UK) admitted that they got it wrong (June 2011) because they were fed untruths by the manufacturers, salesmen and installers. According to them the average price to the end user to put panels on an average semi in the UK costs around £16,000 and that the saving in energy bills is about £70 per year. A quick bash on the calculator and forgetting anything after the decimal point means you would get your money after 228 years. Personally I think even that figure is wrong from what I have read so I stick to my 50 to 80 years but then I may also be wrong.

Most people do no understand this technology and that includes those selling it. Wild claims are made about payback, tax credits etc. The only truth is that you are helping to reduce carbon emissions. If you are extremely environmentally friendly and can afford not to worry about saving money then it's a nice thing to do. France however has the smallest carbon footprint in Europe because it uses nuclear power.

Source

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[quote user="Quillan"][quote user="Bill"]

solar arrays !  

I'm  not sure if the french are subsidising, but many governments are...  seems to make a big difference, payback in this country is about ten years, disregarding inflation/deflation  of energy.

farmer up to road (UK)  has gone barmy and spent 60,000 on one array on his barn.. put up the barn specially.. he is anticipating even faster pay back as claims agaisnt tax , and gets his vat back as registered.. If the gites are a biz niz, then perhaps the vat /cost is claimable .

rgds

bill

[/quote]

I don't know where you get that figure from but The Energy Saving Trust (UK) admitted that they got it wrong (June 2011) because they were fed untruths by the manufacturers, salesmen and installers. According to them the average price to the end user to put panels on an average semi in the UK costs around £16,000 and that the saving in energy bills is about £70 per year. A quick bash on the calculator and forgetting anything after the decimal point means you would get your money after 228 years. Personally I think even that figure is wrong from what I have read so I stick to my 50 to 80 years but then I may also be wrong.

Most people do no understand this technology and that includes those selling it. Wild claims are made about payback, tax credits etc. The only truth is that you are helping to reduce carbon emissions. If you are extremely environmentally friendly and can afford not to worry about saving money then it's a nice thing to do. France however has the smallest carbon footprint in Europe because it uses nuclear power.

Source

[/quote]   Sadly the carbon arguement for PV doesn't add up either...I am with Quillan on this...the manufacture of the panels themselves is very carbon heavy as is their transportation usually from China etc.
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I wonder about these 'green enregy' sources. If you ignore global warming, solar panels will be extracting heat from the sun - what changes might that make. Then there are wind turbines taking energy out of the wind, so this must surely have an effect on the weather
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I fitted evacuated tubes for water heating a few tears ago and have been very happy with it so far. In the winter we use the electric immersion to back it up, but still get solar energy on sunny days.

I have also fitted an air to air heat pump in the bedroom a couple of weeks ago and am most impressed. I also went for a Brico Depot inverter system. The intention was to back up the wood burner in the lounge so I fitted it in the bedroom, it is so good that the wood burner now backs up the heat pump. I was amazed last week Tuesday, when I had to go out in the morning for a long drive and the temperatures on the outside thermometer and on the car were showing -19c, that the heat pump was pushing out nice warm air.

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I know we are drifting from heat to power and both are interesting subjects especially if your renovating and intend to run a business. Anything that reduces your outgoings has to be an advantage. So before I give another suggestion for heating there is something I would like to say about the PV power side.

One issue with generating electricity yourself in France is that for some strange reason your are, I believe, obliged to sell it to EDF in total then buy it back. This is unlike the UK where you can actually disconnect yourself from the grid, known as 'off grid living'. If your building from scratch you can design a system that gives you power from stored electricity (either deep cycle batteries or second hand submarine batteries) created by PV panels and other sources (wind or water generated). You obviously need to run your house on minimum electricity and design it to make the best use of natural light. It can be done and there was a house on Grand Designs where somebody achieved this.

Going back to heating another method you could employ is a biomass boiler/furnace and if you have quite a bit of land look at growing willow. This is very fast growing stuff and can be cut after three years growth and then burnt (it burns very hot). There is some basic information here http://www.diversitec.co.uk/willow.php which is a good starting point to investigate further. I am led to believe from when I looked in to it that you can use most boilers designed to use pellets as a fuel. The issue of course is you need a lot of land to grow it because you farm it in three or four year cycles. It is also classed as 'carbon neutral'. Payback is quicker because after the initial outlay there are little or no further costs for creating the fuel. It depends what you want to do, your ethics with regards to the environment etc. There is no 're-seeding' because you cut the tops off then they re-sprout hence they are simple to grow and harvest.

I always look at things from the point of view that for example if I buy a boiler and its the same price be it pellet, gas or oil what extra equipment would I need to grow, harvest and dry willow for fuel. If we say a 20k outlay I would compare this to the cost of buying fuel like gas or oil. How many years of gas or oil could I buy for 20k and how long will I live in the property. In the long run it may be actually cheaper for me to stick with gas or oil as I may well move or I might be dead by the time I equal the 20k in which case there is no advantage for me.

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[quote user="Bob T"]I fitted evacuated tubes for water heating a few tears ago and have been very happy with it so far. In the winter we use the electric immersion to back it up, but still get solar energy on sunny days.
I have also fitted an air to air heat pump in the bedroom a couple of weeks ago and am most impressed. I also went for a Brico Depot inverter system. The intention was to back up the wood burner in the lounge so I fitted it in the bedroom, it is so good that the wood burner now backs up the heat pump. I was amazed last week Tuesday, when I had to go out in the morning for a long drive and the temperatures on the outside thermometer and on the car were showing -19c, that the heat pump was pushing out nice warm air.
[/quote]

I quite like the type of heat as well. I mean if it gives out 3kw it's not like standing in front of a 3kw electric blower heater, its more subtle. It's difficult to explain to somebody who has never experienced it. It won't be much longer before your investing in a few more I bet. [;-)]

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is this the beasty you are all  talking about as inverters ? 

 

Bill

 

POMPE A CHALEUR CONSOLE DC INVERTER 5000 W

la pompe à chaleur
995€00Dont 13,04 € d’éco participation

Pour une pièce jusqu'à 60 m² (150 m"). Puissance : 5000 W en froid et 6000 W en chaud. Consommation : 1550 W en froid et 1650 W en chaud. COP : 3,62 en chaud. dB intérieur : 38 db.

 

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[quote user="Bill"]

is this the beasty you are all  talking about as inverters ? 

 

Bill

 

POMPE A CHALEUR CONSOLE DC INVERTER 5000 W

la pompe à chaleur
995€00Dont 13,04 € d’éco participation

Pour une pièce jusqu'à 60 m² (150 m"). Puissance : 5000 W en froid et 6000 W en chaud. Consommation : 1550 W en froid et 1650 W en chaud. COP : 3,62 en chaud. dB intérieur : 38 db.

 [/quote]

Yes that is the one. Just as Quillan says it just pumps out hot air and warms the whole area of a room and also half the single story house in my case, should have bought it years ago!

Added to that there is no longer damp anywhere, even on the windows in the morning.

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One of them, you need to pick the right size for the room. Also they make a few they make a few assumptions when 'sizing' the units to room size because it can be a bit complicated. You need to know room size, window size and glazing type, how many people will be in the room, general level on wall insulation etc to get the right size unit. If you want to work it out a bit better here is a link that might help.

http://www.ukofficedirect.co.uk/calculating_what_air_conditioner_cp.aspx

Although this is primarily about cooling it also works for heating although you have to change the calculations a bit as your adding heat not trying to get rid of it.

You may also find that a dual split unit (thats two inside units and one outside unit) may work better for you if you have say an 'L' shaped room.

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It's not particularly difficult to work out the heat input required for a room. You need all the sizes of course plus the U factors of the structure and the windows / doors, the reference outside temperature, air change requirement, the desired temperature in the room and the temperature of each adjoining room

It's basic maths really once you have the formula.

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