Hi there,
I posted this thread initially in the intro section so probably not much viewed there. I'd really appreciate any comment from one or more of you pro guys.
I’ve a long term barn renovation project in Normandy and would like to ask for comment on my proposed central heating system.
The boiler will be a woodburning stove (Villager AHI) with a quoted 14kw boiler output. I’ll route this through a zone valve to a radiator system and also into the primary heating coil of an unvented twin coil 210L Gledhill hot water cylinder. I’m aware of the UK regulations for solid fuel systems and unvented cylinders, but understand through the forums that it will be possible in France provided the boiler system is open (ie fed from a header tank). I’ll also have a dedicated heat sink radiator and an auto valve set to open to drain under no power condition.
I intend to have underfloor heating for part of the barn – I’ve provisionally planned to install 3x12m2 “boxes” from Floorheater.co.uk, and will provide this heat from an 8.5kw air source heat pump. The balance of the heat pump output will be routed through the secondary coil in the hot water cylinder.
I’d like to know if I’m on the right track and also if I should be looking at thermal stores which I’ve tried to avoid on cost grounds. The floor area is 150m2, with only me and the missus normally in residence
Regards,
jbolland
Why bother with a Gledhill cylinder, do you know what the water pressure is in France??, normally 3 bar, don't try and adapt the UK style of plumbing to France, it don't work like that, pipe sizes are different, apart from iron and the threads, and they are all parallel
If you go the UK route it will mean a trip back to the UK if you have forgotten anything or want spares, etc
Either post on the forum or use the PM system if you want to know more, I live in France and finished my working time in France
This might help you its a few notes I did for a French forum
Plumbing a house
Hot & Cold Water
The Basics
For a layman I would advise them to use plastic piping, but not the c-pvc pipe (the joints need 24 hours to set, and it can be brittle, and be broken easily), rectulated-polyethylene, or cross linked polyethylene (known as PEX or Alphacan etc) for fitting the fittings to the tube a special tool is used, to draw up a brass ring over the plastic tube after a brass insert is fitted into the tube compressing the plastic pipe wall on to the ridges on the insert
If you feel competent in using an oxy acetylene torch, or a gas torch, for hard soldering the copper tube, I would advise using copper tube, in France all copper tube for water is hard soldered, very few compression joints are used by the French plumbers
Both forms of tubing have good and bad points
The plastic tube easy to work with, no scrap value (no theft from an unoccupied site) ideally needs a special cutter to cut the tube cleanly, needs a special crimping tool (costly), the tube needs a special former to stop the tube from 'throating' or collapsing when bent on a tight radius, joints can leak if made wthout care; pipe sizes: 12mm, 16mm, 20mm; in 5 mtr, 10 mtr, 25 tr, or 50mtr coils; with or without an outer sleeve (gaine in French)
The copper tube, can come in "dead" hard temper, of 1 mtr, 2 mtr, 3 mtr, or 4 mtr lengths, or in "dead" soft temper coils, of 5mtr, 10 mtr, 25 mtr, or 50 mtr coils; copper tube in France is 1mm wall thickness, anf comes in equal pipe dimensions and starts at 6mm id/8mm od, (so you would ask for 10/12 mm tube if you wanted a pipe with a 10mm internal bore), and rises in 2mm steps ie 6,8,10,12,14,16,18,20,22 mm, for normal house plumbing unless the copper tube is soft temper, it needs to be anneled to soften it prior to being bent, pricey to buy (and has a potential for theft from site) copper tube in coils can be also obtained with a 'light' plastic covered insulation, a hard solder (99% copper, 1% phosphorus) is used for the jointing the copper tubes, SOFT SOLDER is not used by French plumbers
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Plumbing a French house is a little different to the plumbing in the UK
First all the water supply is off the main supply (no water storage tanks in the roof space to get contaminated), which is normaly around 3 Bar pressure (1 Bar =1 Atmosphere approx 14.5 lbs a square inch) or about 45lbs sq inch, this pressure means that smaller pipe sizes can be used, both for the hot and cold supplies; if the mains pressure is greater than 3 Bar a pressure reduceing valve needs to be fitted just after the main stop valve where it comes into the building
The modern French way of plumbing a house is to use manifolds for the distribution of both hot and cold water inside the house, a set of manifolds per floor is normal, if the manifolds are fitted with quarter turn valves on the branches, a single appliance can be isolated, these manifolds an either be made on site (to suit the job in-hand) or purchased (3, 4, or 6 outlets, but can be joined together for more outlets) all tube copper or plastic where its buried in the floor or wall must be covered with a plastic gaine
The hot water cylinder is normally a mains water fed, electricaly heated, 200 litres is normal capacity, but 100 ltr 150 ltr and 300 ltr can be obtained, and is a glass lined steel cylinder with a 75mm insulating and a light steel cover jacket, indirect cylinders (with an internal coil heated by a boiler), some boilers come with an integral stainless steel cylinder
The incoming mains water, hot water cylinder, and quite often the boiler as well, are often fitted in the garage, this is where the ground floor manifolds would be fitted close to the incoming water and hot water cylinder and the tubes fitted in the 'first fix' stage are connected
First fix is where the tubes are laid under the concrete slab, or screed, using a manifold system normally allows the pipe work to be laid in one length without any joints in the concrete slab or screed which can be reassuring that there are no leaks are in the buried part of the building
Normal Pipe Sizes for different appliances etc, Note all sizes are internal diameter
Incoming water supply: Copper tube 22mm, Medium Density Polyethelyne (French, black with 4 light blue stripes) 19mm id x 25mm od : Note in old buildings lead pipe can still be found this should be replaced, iron pipe can also be found this needs to be replaced, PVC pipe can also be found, do not touch it can be brittle and snap on you
Hot water cylinder 22 mm copper for at least the first metre, if changeing to plastic
Bath 16 mm or 18 mm
Shower 14 mm or 16 mm
Wash hand basin 12 mm
Bidets 12 mm or 14mm
Kitchen sink 14 mm
Tap for a washing machine or dish washer 12 mm
W/C 10mm
Out side tap 14 mm
Brossett (part of the Wolsey group) do metal expansion tanks semi closed top with a tapping welded into the bottom "vasse d'expansion" in French, most ball valves are 3/8 with a small copper float if you are lucky, otherwise it a bit of plastic on the end of the arm
The biggest thing that you would have to worry about in winter is the power going off, maybe for a few hours but it could be for a few days or more, if you are out in the sticks, and want a fair chunk of electricity, you might have to settle for a 3 phase supply, or pay mega Euros and wait for a new line to be run in
