Anybody got any figures for these (and ideally pointers to sources of such
figures)? I can't find them in Part L or BS5449(1990). The BS has values for
floors with Bare boards and "Parquet, lino, rubber" (rubber?!): I wouldn't
have expected them to have laminate in 1990, but I'm sure we had carpets
even back in those days!

I know I could calculate the U of the flat roof from its component
materials - I'm just being lazy! I am surprised they don't include it
though.

--
John Stumbles
-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-|-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
-+
I've got a book about motivation but I've never got round to reading it

On Sun, 4 Jan 2004 15:22:15 -0000, "John Stumbles"
] wrote:

Anybody got any figures for these (and ideally pointers to sources of such
figures)? I can't find them in Part L or BS5449(1990). The BS has values for
floors with Bare boards and "Parquet, lino, rubber" (rubber?!): I wouldn't
have expected them to have laminate in 1990, but I'm sure we had carpets
even back in those days!

There are tables in the help files of the Myson and the Barlo heatloss
calculating software. If you want the Myson one (their web site is
under construction) I can mail it to you.
There is also a good table and sets of numbers the HVCA Central
Heating Design Guide.

For the roof, the main factor is going to be the amount of insulation.

Figures I have are 2.04 for uninsulated, 0.80 for 25mm and 0.54 for
50mm. Probably after that, the figure is going to tend towards the
U value of the insulation and the rest becomes almost irrelevant.


For the floor, you have to take into account the perimeter/area factor
if it is a ground floor so there are tables of numbers rather than
single figures.



I know I could calculate the U of the flat roof from its component
materials - I'm just being lazy! I am surprised they don't include it
though.

..andy

To email, substitute .nospam with .gl

"Andy Hall" wrote in message
...
On Sun, 4 Jan 2004 15:22:15 -0000, "John Stumbles"
] wrote:

Anybody got any figures for these (and ideally pointers to sources of
such
figures)? I can't find them in Part L or BS5449(1990). The BS has values
for
floors with Bare boards and "Parquet, lino, rubber" (rubber?!): I
wouldn't
have expected them to have laminate in 1990, but I'm sure we had carpets
even back in those days!

There are tables in the help files of the Myson and the Barlo heatloss
calculating software. If you want the Myson one (their web site is
under construction) I can mail it to you.

Yes please; I thought I had a copy somewhere but can't find it now I need it
:-(

The Barlo one's tables seem to be cribbed straight from the BS.

There is also a good table and sets of numbers the HVCA Central
Heating Design Guide.

"Domestic Heating Design Guide", £20, treeware perhaps?

For the roof, the main factor is going to be the amount of insulation.

Figures I have are 2.04 for uninsulated, 0.80 for 25mm and 0.54 for
50mm. Probably after that, the figure is going to tend towards the
U value of the insulation and the rest becomes almost irrelevant.

I'd expect it to have 100mm glass fibre but I'd need to ask the guy who put
it up. I'll shoot for 0.5 which should be close enough for jazz.


For the floor, you have to take into account the perimeter/area factor
if it is a ground floor so there are tables of numbers rather than
single figures.

The BS just has a couple of fudge factors for different floor areas of solid
floors (reflected in Barlo's 110sqm, 50sqm and Terraced house options).



--
John Stumbles
-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-|-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
-+
Thank God I'm an atheist

On Sun, 4 Jan 2004 23:23:59 -0000, "John Stumbles"
] wrote:

"Andy Hall" wrote in message
.. .
On Sun, 4 Jan 2004 15:22:15 -0000, "John Stumbles"
] wrote:

Anybody got any figures for these (and ideally pointers to sources of
such
figures)? I can't find them in Part L or BS5449(1990). The BS has values
for
floors with Bare boards and "Parquet, lino, rubber" (rubber?!): I
wouldn't
have expected them to have laminate in 1990, but I'm sure we had carpets
even back in those days!

There are tables in the help files of the Myson and the Barlo heatloss
calculating software. If you want the Myson one (their web site is
under construction) I can mail it to you.

Yes please; I thought I had a copy somewhere but can't find it now I need it

On its way to you....


:-(

The Barlo one's tables seem to be cribbed straight from the BS.

There is also a good table and sets of numbers the HVCA Central
Heating Design Guide.

"Domestic Heating Design Guide", £20, treeware perhaps?

Yep. www.hvca.org.uk

£19.50

It has a bunch of other useful data as well such as pipe sizing,
radiator derating, pressure vessel sizing. I found it useful to
have everything in one place.


For the roof, the main factor is going to be the amount of insulation.

Figures I have are 2.04 for uninsulated, 0.80 for 25mm and 0.54 for
50mm. Probably after that, the figure is going to tend towards the
U value of the insulation and the rest becomes almost irrelevant.

I'd expect it to have 100mm glass fibre but I'd need to ask the guy who put
it up. I'll shoot for 0.5 which should be close enough for jazz.


Certainly at 100mm and up figures get quite close to the material's U
value. In reality the loss will be a shade less, but that goes in
the right direction for a heating design.



For the floor, you have to take into account the perimeter/area factor
if it is a ground floor so there are tables of numbers rather than
single figures.

The BS just has a couple of fudge factors for different floor areas of solid
floors (reflected in Barlo's 110sqm, 50sqm and Terraced house options).

For a boarded floor (non T&G), I suppose one should consider the
draught proofing effect of the carpet as well, but that is pretty hard
to assess.....

..andy

To email, substitute .nospam with .gl

"Andy Hall" wrote in message
...
On Sun, 4 Jan 2004 23:23:59 -0000, "John Stumbles"
] wrote:

"Andy Hall" wrote in message
.. .
On Sun, 4 Jan 2004 15:22:15 -0000, "John Stumbles"
] wrote:

Anybody got any figures for these (and ideally pointers to sources of
such
figures)? I can't find them in Part L or BS5449(1990). The BS has
values
for
floors with Bare boards and "Parquet, lino, rubber" (rubber?!): I
wouldn't
have expected them to have laminate in 1990, but I'm sure we had
carpets
even back in those days!

There are tables in the help files of the Myson and the Barlo heatloss
calculating software. If you want the Myson one (their web site is
under construction) I can mail it to you.

Yes please; I thought I had a copy somewhere but can't find it now I need
it

On its way to you....


Thanks


---8---


For the floor, you have to take into account the perimeter/area factor
if it is a ground floor so there are tables of numbers rather than
single figures.

The BS just has a couple of fudge factors for different floor areas of
solid
floors (reflected in Barlo's 110sqm, 50sqm and Terraced house options).

For a boarded floor (non T&G), I suppose one should consider the
draught proofing effect of the carpet as well, but that is pretty hard
to assess.....

Well it's all pretty approximate (unless you get into the sort of detail in
Part L1) so I'm surprised they haven't at least included some average-ish
sort of figures e.g. cheap'n'nasty rubber-backed | deluxe thick pile on
cushioned underlay.

I see Barlo's help file also refers to the BS and shows the same table (as
also in the Barlo) but then goes on to describe the P/A method. However
their calcs seem to just use the BS table - no P/A.

I suppose for uninsulated suspended floors the heat loss through the floor
vastly exceeds the loss round the peripheries so you can in practice pretty
much ignore P/A - ?



--
John Stumbles
-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-|-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
-+
Women always generalise

On Mon, 5 Jan 2004 01:51:08 -0000, "John Stumbles"
] wrote:




For the floor, you have to take into account the perimeter/area factor

if it is a ground floor so there are tables of numbers rather than
single figures.

The BS just has a couple of fudge factors for different floor areas of
solid
floors (reflected in Barlo's 110sqm, 50sqm and Terraced house options).

For a boarded floor (non T&G), I suppose one should consider the
draught proofing effect of the carpet as well, but that is pretty hard
to assess.....

Well it's all pretty approximate (unless you get into the sort of detail in
Part L1) so I'm surprised they haven't at least included some average-ish
sort of figures e.g. cheap'n'nasty rubber-backed | deluxe thick pile on
cushioned underlay.

I see Barlo's help file also refers to the BS and shows the same table (as
also in the Barlo) but then goes on to describe the P/A method. However
their calcs seem to just use the BS table - no P/A.

I suppose for uninsulated suspended floors the heat loss through the floor
vastly exceeds the loss round the peripheries so you can in practice pretty
much ignore P/A - ?

This is basically what TNP said. For a suspended block floor, you
could effectively treat it as a wall on the basis that the outside
temperature is across the entire underside. This would give a worse
heat loss calculation than using the P/A factor, but for a heating
design will mean that you err on the side of more heat provision.

For timber floors, possibly the U values published assume no P/A
anyway.

Obviously it's a different situation if you are trying to demonstrate
that a new house construction falls within energy consumption
guidelines as opposed to a heating design for an existing property
where you want to make sure that there is adequate heat provisioning.
Generally on a property without cavity insulation, the largest heat
losses tend to be through the walls anyway, and the floors about third
on the pecking order.

Another factor is how does one treat party walls? Should it be to
assume that next door has no heating and that therefore the party wall
is effectively external, or that next door has heating and that
therefore there is a net zero transfer - or something in between?
If you consider a typical terraced property, they are often three
times as deep as wide, so the party wall areas are substantial in
comparison to the external.




..andy

To email, substitute .nospam with .gl

Andy Hall wrote:



For the floor, you have to take into account the perimeter/area factor
if it is a ground floor so there are tables of numbers rather than
single figures.


In any case teh tables are not hugely accurate. In my case they are
probabvly accurate for a floor that is unvented underneath, but when the
east wind blows and the stupid an unncessary underfloor vents (its a
suspended block and beam floor) let oit all in, it drops in temperature
a LOT even WITH insulation.

Anyone know what a rotless suspebed concrete floor has to have
underfloor vents? The Building inspector muttered something about
letting flood water out...Oh well. At least it allows me to pick up air
for open fires by punching down a foot into the void...

On Sun, 04 Jan 2004 23:21:28 +0000, The Natural Philosopher
wrote:

Andy Hall wrote:



For the floor, you have to take into account the perimeter/area factor
if it is a ground floor so there are tables of numbers rather than
single figures.


In any case teh tables are not hugely accurate. In my case they are
probabvly accurate for a floor that is unvented underneath, but when the
east wind blows and the stupid an unncessary underfloor vents (its a
suspended block and beam floor) let oit all in, it drops in temperature
a LOT even WITH insulation.

I suppose you could then treat it as though the entire floor was
exposed to outside temperatures (i.e. like a wall) and ignore the
periphery effect.
For the purposes of a heating requirement calculation, and assuming no
draught through the floor adding to air changes, this would give a
conservative figure (i.e. worse heat loss than it probably is).


Anyone know what a rotless suspebed concrete floor has to have
underfloor vents? The Building inspector muttered something about
letting flood water out...Oh well.

Do they have four toes? I know that there's strange tales from those
parts..... :-)

At least it allows me to pick up air
for open fires by punching down a foot into the void...

You should have built the floor stronger....... ;-)



..andy

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