proposed central heating installation

[jbolland]

Hi, Ive just joined today and would like some advice or comment on the following.
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

 

[migoplumber]

you would need to post a proper schematic drawing, so we can pick holes in it constuctively !!
at first glance 22.5 kw dosnt seem near enough to heat 150m2 + give you hot water ?

good luck
shaun

 

[jbolland]

Hi Shaun,
Thanks for your comments. I'll have a few strategic electrical heaters as well which i hope I won't need too often. I've attached a pdf of the schematic, hope you can make sense of it, sorry the nice colours couldn't come out.
James

 

[migoplumber]

immediate thought is when your wood burning stove is on, and the zone valves are closed, there will be a problem, that needs looking at. your emergency heat source needs to be directly linked on your boiler primaries before any valves. make yourself a header circuit up, then go on to your zone valves.
cant see a problem with the dhw side.
still dont think you have enough kw for your heating side tho, but that can be fixed after its all up and running by tagging another sytem boiler in parrallel to your stove. just make sure you throw in an extra gas/oil line just in case.

good luck
shaun