Re: Re: Zoned Heating Control

[Chris Hunter <cjhunter@xxxxxxxxxxxx>]

Richard -

thanks ... interesting ...

rather than temperature gradient, I guess it'll be rate of heat
supply, that would be the constant, for a given room, with a higher
temperature gradient between UFH pipe & air in the room being needed
to drive the heat through if there's more resistance, because of
carpet or underlay, say ... and the higher temperature in the pipes
that that would need would lead to some loss of efficiency, thanks to
greater heat losses upstream from the UFH and basic thermodynamics
(small temperature differences being more efficient in any
thermodynamic / heat-cycle, IIRC) ...

'must say, I'm edgy about loose-floating the wooden covering &
leaving a gap at the edge .... noise issues & what happens if there's
a flood !   Plus, we intend not having skirting boards !

when we started our build, we had floor-grade hardboard on our list
of options ... didn't sound a good idea, until I got a sample of the
material ... it's still an option (suitably sealed) !

'wonder if it would be possible to leave the screed (anhydrous)
uncovered ('might have to be sealed, I guess) ... or if an epoxy
paint could be good ??

if it was up to me, I think I'd go for welded linoleum, but 'wife
wants wood !

Chris



On 29 Apr 2007, at 09:13, rb_ziggy wrote:

> Bit of a gap - been away since your post!
>
> I wouldn't worry about the underlay. All these 'engineered' wooden
> floors work this way.  The planks are glued/locked together and the
> whole floor 'floats' loose on the screed.  This is what allows it to
> expand and contract without self destructing.  As long as the whole
> floor is subject to the same conditions (and it will be with UF) then
> there are no problems with differential expansion (i.e caused by damp
> one side and dry the other).
>
> I think the underlay does two things, it reduces noise (as stated
> before) and it can (if you use the thick stuff) give a bit more
> insulation to the slab.  You don't need the latter in a under-slab
> insulated house so just go for the 2-3mm underlay.
>
> It doesn't need any additional calculations / pipe as such. (Adding
> more pipe running at a lower temperature is actually a waste of money
> as it's the temperature gradient that is the determining factor.)
> From what I remember, the wood + underlay creates no more of a thermal
> barrier than carpet. The company supplying can easily take these
> factors into account when they design the pipe layout.  Most supply
> you with a specific piping layout on your plans.
>
> With underlay, it doesnt feel markedly 'softer' - just like a 'normal'
> (slightly 'sprung'???) wood floor.  But it's a lot less hard than
> ceramic tiles.
>
> We something like 120m2 of engineered wood flooring over uf and it
> works flawlessly for over 5 years.
>
> Richard
>
> --- In ukha_d@xxxxxxx, Chris Hunter <cjhunter@...> wrote:
>>
>> Underlay ???   'hadn't thought of that !
>>
>> I imagined it would be glued to the screed, rather than laid
>> loose ... interlocked, presumably, but loose ... ?
>>
>> which seems odd, because ceramic tiles wouldn't be laid loose,
>> surely, so glues must be available ... ?
>>
>> 'wonder how much hotter must the water be to cope with this ...
maybe
>> it's a specially conductive underlay ... maybe doubling the pipe
>> would compensate (IIRC Ian's used more pipe, to run cooler, so
might
>> work) ... ?
>>
>> being softer underfoot might be good, of course, but it rather
puts
>> me off the idea !
>>
>> Chris
>>
>>
>>
>>
>> On 19 Apr 2007, at 01:10, rb_ziggy wrote:
>>
>>> We have a Kahrs 'engineered' (i.e. laminated not laminate)
wood
>>> floor
>>> throughout the ground floor.  Absolutely no probs with UF in
over 5
>>> years.  Works fine.
>>>
>>> But as Nigel says, don't go for the thick (i.e. insulating)
>>> underlay,
>>> that is rather counter-productive.  (N.B. do use underlay
though, a
>>> friend laid the same floating flooring without and it sounded
like a
>>> drum when the kids ran around).
>>
>>
>>
>> [Non-text portions of this message have been removed]
>>
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