IMM wrote:

"vivienne wykes" wrote in message
.uk...

Hi thanks for that,

I am converting a barn in the Scottish Borders. It has poured concrete on

th

ground floor and joists on the first floor.
When I do the heating it will be justr the joists no existing floorboards
due to woodworm....


Make sure the ground floor is very well insulated. The insulation should be
like a tray wit the side running up the wall to poured concrete level.

So fra so go, but teh 'wit' bit as usual leaves one confused..IMM trying
being witless.

Put as much insulation in the bar as possible,

Thats to keep the ice from melting in your gin and tonic of course.


and then size up the UFH from
there.

Whatever that means. I am sure its really profound.

You may only require UFH on the ground floor, if insulated well
enough.


Oddly, I find that wrapping UFH in insulation reduces its effectiveness,
but grammar, punctuation and the ability to understand or communicate
the fabulous ideas IMM has read about in glossy brochures has never been
'our Johns' strong point.


However, yes, attempting to remove the babble and concentrate on the
facts (although I assumed you would glean those from reading up) its
best under concrete ground floors over as much insulation as you can
stuff UNDER the FLOOR (not round the heating pipes!) in order to
maximise the losses to the room (wanted) to the losses into the ground
(wasted, unless breeding earthworms for profit or protein)

Unless you are largely open plan however, upstairs will need heating:
The amount of 'superinsulation' Our John would have you install along
with completely sealing each upper room hermetically is simply infeasible.

I chickened out on a similar project and installed hot air blowers
upstairs fed from hot water. But on reflection it would have been not
too hard to do UFH on the upper story. The big problem is stopping heat
going down to the floor below, (extra insulation between floors) and
making sure that the floor structure can stand the variation between
high summer humidity, and very low winter humidity (when heated) without
deformation. Chip flooring is fine if carpetetd, though teh insulatin
ofte carpet underla is undesirable, laminate is excellent from a
technical point of view, but you may hate it, tiles are good, but you
need to be wary ogf real wood planks: These can easily warp and cup
massively. Its not insoluble, but it needs consideration.


You do need to think about thermostats and control systems tho. If the
house is massive in thermal inertia and well insulated the ground floor
is probably OK on a simple 'on all night' or 'on all the time' basis
with a single overall thermostat to control it - I have this, and it
works very well.

However upstairs where the all timber construction is much faster to
heat up and quicker to cool, I find that individual room controls plus
an overall different timing is required. Therefore I have a three zone
controller (UFH, Upstairs hot air, and Hot water) and stats on each
upstairs room. Its also nice to be able to disable unoccupied spare rooms.

For wet UFH heating upstairs I think standard TRV's on the feed to each
room are probably no worse that electrical stats and wires coming back
to the manifold. However you do need to consider the case where all
upstairs rooms are essentially 'shut down' but there is no overall
thermostat to cut the pump.

I have solved that one in the past by allowing one room - usually a
bathroom of small dimension, to run unregulated with a massive heat
input. I like hot bathrooms. This at least gives the pump something less
than a complete blocked circuit to pump.

Or if you have e.g. an unheated upper corridorr, you can put a master
zone stat in that. Esssentiall teh zone stat should be where the heating
outptout is lowest so is the last bit to warm up.

The really class job is to split the house into two zones for two
separate timers, and one circuit per room, use electrical 'stats in each
room feeding motorised valves on the manifold, with an overall wired OR
circuit so that any stats that demands heat will set the pump going.

Since you need a separate pump also to run DHW, you tend to need a relay
in the control wiring as well.

None of this is rocket science, but if you are condsidering a class
system, make sure you run wires from a stat in each room back to your
'control center' and don't understimate the size of that - all my stuff
is in a large cupbiardd in the boiler room where it can be got at, and
there us a lot of pipework and wire in there too

If you want to enter into detailed discussion its probably best to take
this offline to e-mail, as it gets tedious