Rick Dipper wrote:

I have worked out the U values of the insulation I intend to use in my
cavity walls, I have 2 solutions

1) Blocks -celotex-rockwall = 0.224 W/m2K
2) Blocks -2 * rockwall = 0.255 W/m2K

I did not take account of the external wall, plaster, mortar or wall
ties in working out these figures. The external walls are 600mm stone
walls.

Normally I would go for option 1, but its arround twice the cost of
option 2, a whole lot more difficult to install (I am building the
inner wall second) and there is not a big difference in the insulation
values.

Any ideas on how I work out if its worth it ?

Is it as simple as working out the temperature difference, the surface
area of the wall, to work out the loss via the wall, and then mutiply
by the cost of a watt of heat ?

My thoughts right now are to save the money, and use it to put extra
into the roofspace.

Thanks
Rick


I went with 2x rockwool purely on cost. It was good enough.

Despite IMM's blatherings, once you meet building regs U values, you are
already into the law of diminshing returns as unless you put in heat
recovery ventilation, and have no windows, the majority of the heat loss
will be via the windows and ventilation - which you need to avoid steamy
damp atmospheres in winter anyway.

IMM wrote:

"Ian Stirling" wrote in message
...

Rick Dipper wrote:

I have worked out the U values of the insulation I intend to use in my
cavity walls, I have 2 solutions

1) Blocks -celotex-rockwall = 0.224 W/m2K
2) Blocks -2 * rockwall = 0.255 W/m2K


0.255 is poor. You should be aiming for 0.1ish


0.3 is adequate.

Imm is talking ********. Don't ingore the rest of the walls either. They
make a significant, but not dominating, contribution.

"The Natural Philosopher" wrote in message
...
IMM wrote:

"Ian Stirling" wrote in message
...

Rick Dipper wrote:

I have worked out the U values of the insulation I intend to use in my
cavity walls, I have 2 solutions

1) Blocks -celotex-rockwall = 0.224 W/m2K
2) Blocks -2 * rockwall = 0.255 W/m2K


0.255 is poor. You should be aiming for 0.1ish


0.3 is adequate.

Imm is talking ********.

You really don't, know do you. 0.1ish is the aim.

"Rick Dipper" wrote in message
...

I have worked out the U values of the insulation I intend to use in my
cavity walls, I have 2 solutions

1) Blocks -celotex-rockwall = 0.224 W/m2K
2) Blocks -2 * rockwall = 0.255 W/m2K

......
Another problem that can arise with very high levels of insulation and a
well sealed house, is large amounts of condensation.
In Scandinavian new builds I've seen this has been specially catered for.

"The Natural Philosopher" wrote in message
...
Rick Dipper wrote:

I have worked out the U values of the insulation I intend to use in my
cavity walls, I have 2 solutions

1) Blocks -celotex-rockwall = 0.224 W/m2K
2) Blocks -2 * rockwall = 0.255 W/m2K

I did not take account of the external wall, plaster, mortar or wall
ties in working out these figures. The external walls are 600mm stone
walls.

Normally I would go for option 1, but its arround twice the cost of
option 2, a whole lot more difficult to install (I am building the
inner wall second) and there is not a big difference in the insulation
values.

Any ideas on how I work out if its worth it ?

Is it as simple as working out the temperature difference, the surface
area of the wall, to work out the loss via the wall, and then mutiply
by the cost of a watt of heat ?

My thoughts right now are to save the money, and use it to put extra
into the roofspace.

Thanks
Rick


I went with 2x rockwool purely on cost.

El cheapo eh.

It was good enough.

It is not!!!!

Despite IMM's blatherings, once you meet
building regs U values, you are

....insulated well below Germany, Scandinavia, north America and most of
western Europe.

Go for 0.1ish

"Dave Stanton" wrote in message
news
On Fri, 20 Aug 2004 23:26:11 +0100, IMM wrote:


"Rick Dipper" wrote in message
...

More is always better.

Surely the rule of diminishing returns applies here.

Dave



Precisely, and at a certain point negative returns are achieved.

In other words, when the last x mm of insulation takes more energy to
manufacture, distribute, install, and eventually dispose of than it will
ever save over it's expected lifetime, then it has a negative overall
environmental impact.

This cutoff point will also be influenced by the average weather conditions
of the locality. Those advocating movement towards insulation standards
common in Germany, Scandinavia and parts of the North American continent
should remember that they suffer much colder winters than the majority of
the UK which will therefore push the environmental equilibrium towards
installation of more insulation.

--
Richard Sampson

email me at
richard at olifant d-ot co do-t uk

"RichardS" noaccess@invalid wrote in message
.. .
"Dave Stanton" wrote in message
news
On Fri, 20 Aug 2004 23:26:11 +0100, IMM wrote:


"Rick Dipper" wrote in message
...

More is always better.

Surely the rule of diminishing returns applies here.

Precisely, and at a certain point negative returns are achieved.

In other words, when the last x mm of insulation takes more energy to
manufacture, distribute, install, and eventually dispose of than it will
ever save over it's expected lifetime, then it has a negative overall
environmental impact.

This cutoff point will also be influenced by the average weather
conditions
of the locality. Those advocating movement towards insulation standards
common in Germany, Scandinavia and parts of the North American continent
should remember that they suffer much colder winters than the majority of
the UK which will therefore push the environmental equilibrium towards
installation of more insulation.

Nice try, but flawed logic. The cut off point is when you don't require a
full heating system. That is simple. Then the gains start to really add up.
What is not really taken into account is the cooling effect insulation can
have in hot summers, which appear to be on the way. So, the gains,
especially in comfort conditions in winter and summer, increase yet again.

Insulation to the point of not requiring a full heating system is a win, win
situation all the way. All the knowledgeable experts who write on this
subject all agree that superinsulation is well worth it.

Don't guess, find out.

IMM wrote:

"RichardS" noaccess@invalid wrote in message

of the locality. Those advocating movement towards insulation standards
common in Germany, Scandinavia and parts of the North American continent
should remember that they suffer much colder winters than the majority of
the UK which will therefore push the environmental equilibrium towards
installation of more insulation.

Nice try, but flawed logic. The cut off point is when you don't require a
full heating system. That is simple. Then the gains start to really add up.

It is safe to assume you will still want hot water, hence you still need
a boiler. Yes you can fit fewer or smaller radiators but that does not
represent much capital cost saving (given that you can install a full
heating system for under 3K - you may only save 1K capital outlay). You
seem to be recommending spending several times that cost in PIR foam
alone before you get onto ventilation with heat recovery. It may take a
lifetime to recover the capital costs in reduced energy usage.

What is not really taken into account is the cooling effect insulation can
have in hot summers, which appear to be on the way. So, the gains,

Sorry - but this is nonsense. No amount of insulation will have a
"cooling effect".

More insulation will reduce the rate of heat gain inside the house, but
will also ensure that once it has gained the heat (which it inevitably
will) it will be harder to dissipate it. It will only take a few days of
hot humid weather to get the inside of the house unpleasantly hot - no
matter how well you insulate it. You still need windows (which are not
going to have u values of 0.1), you still get solar gain, and you still
need to open doors to get in and out of the building, allowing air changes.

Insulation to the point of not requiring a full heating system is a win, win

Not if you reach the point of never recovering from the environmental
impact of building the thing, during the lifetime of the property. Not
if you never recover the capital outlay in lower energy bills.

situation all the way. All the knowledgeable experts who write on this
subject all agree that superinsulation is well worth it.

Where "knowledgeable" = supports your point of view no doubt?

You can generally find experts who will support any point of view you
choose, so this is not really adding any weight to the argument.



--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

"John Rumm" wrote in message
...
IMM wrote:

"RichardS" noaccess@invalid wrote in message

of the locality. Those advocating movement towards insulation standards
common in Germany, Scandinavia and parts of the North American continent
should remember that they suffer much colder winters than the majority
of
the UK which will therefore push the environmental equilibrium towards
installation of more insulation.

Nice try, but flawed logic. The cut off point is when you don't require
a
full heating system. That is simple. Then the gains start to really add
up.

It is safe to assume you will still want
hot water, hence you still need
a boiler.

Maybe.

Yes you can fit fewer or smaller
radiators but that does not
represent much capital cost saving
(given that you can install a full
heating system for under 3K - you
may only save 1K capital outlay).

£3K please get real. In a small terraced house, yes.

You seem to be recommending
spending several times that cost in PIR foam
alone before you get onto ventilation with
heat recovery.

You can do it with PIR foam, or a mix. Using PIR foam on the outer to reduce
thermal bridging and cheaper insulation on the inside.

It may take a lifetime to recover the
capital costs in reduced energy usage.

Nonsense. With a boiler you need annual servicing, assuming you get a pro to
do it. With electricity you do not require servicing. Assuming a new build,
or an extensive renovation, it is worth going all electric as the capital
installation costs are far lower. With a superinsulated home the DHW cost
will exceed the heating cost, so having roof solar panels to fully heat, and
pre-heat, the DHW will reduce electricity running costs. Electric heating
appliances are cheap to buy and install and not annual servicing costs.

In a superinsulated home, a partial electric heating system (which will be
rarely used) and DHW backed up by solar heating will highly cost effective.

What is not really taken into account
is the cooling effect insulation can
have in hot summers, which appear to
be on the way. So, the gains,

Sorry - but this is nonsense. No amount of
insulation will have a "cooling effect".

It keeps heat out and well as in, hence a cooler house. Very simple to
understand.

More insulation will reduce the rate of
heat gain inside the house, but
will also ensure that once it has gained
the heat (which it inevitably
will) it will be harder to dissipate it.

The UK cools at night, so opening windows will disipate heat and the heat
flow also will reverve from inside to outside through the walls

Insulation to the point of not requiring a full heating system is a win,
win

Not if you reach the point of never
recovering from the environmental
impact of building the thing, during
the lifetime of the property. Not
if you never recover the capital outlay
in lower energy bills.

Stop making things up. Do some research. Many eco homes cost little extra,
if at all to build in the first place. You have to get the design right,
which is not difficult.

situation all the way. All the knowledgeable experts who write on this
subject all agree that superinsulation is well worth it.

Where "knowledgeable" = supports your point of view no doubt?

Do some research. Do some reading. Stop trying to be clever and making
things up. My piont of view is based on hard facts, not a whim of a theory.

You can generally find experts who will
support any point of view you
choose, so this is not really adding any
weight to the argument.

What a silly statement.

Another problem that can arise with very high levels of insulation and a
well sealed house, is large amounts of condensation.
In Scandinavian new builds I've seen this has been specially catered for.


Well, sort of. But ..............
Here in Canada with longer colder winters (and often heat leaching winds!)
higher values of the insulation reduce heat loss and therefore the cost of
heating ones home. Since the energy cost increases of the 1970/80s etc. much
thicker insulation has been the 'standard'. Most wood frame houses now have
6 inch wooden stud outer walls filled with insulation and/or sheeted with
foam boards, older homes 4 inch.
But it is the 'vapour barrier' on the warm side of the insulation, whatever
type and thickness it is, that is important. It prevents the warm air from
seeping out into the outer walls and ceilings. Warm air is moist; when it
cools down the moisture in it condenses into water and can cause rot, mould,
damp/wet insulation and even condensation and water droplets in the attic.
(Saw one roof where every nail in the loft/attic was rusty!) same thing, on
a smaller scale, as occasionally happens in large stadia.during a
temperature change. i.e. "It rains indoors".
From time to time our National Government has provided incentives to
increase insulation values, typically and easily by adding several
additional inches to ceilings. Often easy to do using 'blown in' insulation.
But emphasis is always on proper installation, adding to and not blocking
off attic air circulation vents and stressing the use of proper vapour
barriers and or/sealing leakage up into the roof space.
An improper or missing vapour barrier in the ceilings and no attic
ventilation can spell expensive major problems. See damp attics and peeling
painted trim! One guy had 'mushrooms' (fungus) growing up there!
Most new Canadian houses now to qualify for mortgage, are built to R2000
specification; this does require a 'sealed' vapour barrier house with
extensive use of sealants around all interior wall apertures. That type of
construction therefore requires an air/heat exchanger system which runs
continuously using AC mains and also careful additional ventilation of
bathrooms and cooking areas. Both my daughters houses each about 1500 sq.
feet per one floor plus a 'full basement' are built to this standard are
electrically heated and are very economical and comfortable.
Efficiencies of up to 80% heat recovery are claimed for the air/heat
exchangers but personally I doubt if that is true over a wide range of
temperatures. Not having an air exchanger in this older more 'leaky' and
less efficient house am not familiar with their operation in detail. They do
produce condensate which is drained away by a tube and do need cleaning of
the filters and heat exchanger core fairly often.. (How much water vapour
does a human breathes out during a typical night? A litre or two?
By the way, misunderstandings persists about not allowing the house humidity
to get into the outer walls of older homes. Consequently one hears a lot of
nonsense about 'Not being able to keep paint on my house", among older folks
who built houses in the older traditional way. As to why paint blisters and
peels on the outside lapboards of a painted house. What's happening is that
without vapour barriers and or adequate ventilation moisture condenses as it
meets the cold 'within' the exterior walls and then pushes the paint off!
Houses finished with permeable stain permit that moisture, some will always
occur, to 'breathe' out through the walls. This approach has worked for us
in the two houses we built and have lived in ourselves since 1960. Some
older houses that have been covered over with nice looking? but impermeable
siding, such as vinyl, have suffered some rot within the walls! My neighbour
had to replace most of one end wall of his less than 25 year old house!

"Terry" wrote in message
. ..

Another problem that can arise with very high levels of insulation and a
well sealed house, is large amounts of condensation.
In Scandinavian new builds I've seen this has been specially catered
for.


Well, sort of. But ..............
Here in Canada with longer colder winters (and often heat leaching winds!)
higher values of the insulation reduce heat loss and therefore the cost of
heating ones home. Since the energy cost increases of the 1970/80s etc.
much
thicker insulation has been the 'standard'. Most wood frame houses now
have
6 inch wooden stud outer walls filled with insulation and/or sheeted with
foam boards, older homes 4 inch.
But it is the 'vapour barrier' on the warm side of the insulation,
whatever
type and thickness it is, that is important. It prevents the warm air from
seeping out into the outer walls and ceilings. Warm air is moist; when it
cools down the moisture in it condenses into water and can cause rot,
mould,
damp/wet insulation and even condensation and water droplets in the attic.

It also makes the house air-tight reducing much heat loss in winter, and
gain in the summer. The Canadians have the R2000 standard, which is one the
most advanced in the world, if not the most. The Canadians, say "build
tight, ventilate right".

The Canadians don't just slap up the VCB, as they do here. It is
meticulously installed and properly taped up. The Canadians are
implementing the R2000 standard in the UK and Japan. Canadian companies
harve be involved with Uk companies, as the Uk companies just don't have the
skills levels, or can concenrrate long enough to carry out detailed work.

(Saw one roof where every nail in the loft/attic was rusty!) same thing,
on
a smaller scale, as occasionally happens in large stadia.during a
temperature change. i.e. "It rains indoors".
From time to time our National Government has provided incentives to
increase insulation values, typically and easily by adding several
additional inches to ceilings. Often easy to do using 'blown in'
insulation.
But emphasis is always on proper installation, adding to and not blocking
off attic air circulation vents and stressing the use of proper vapour
barriers and or/sealing leakage up into the roof space.
An improper or missing vapour barrier in the ceilings and no attic
ventilation can spell expensive major problems. See damp attics and
peeling
painted trim! One guy had 'mushrooms' (fungus) growing up there!
Most new Canadian houses now to qualify for mortgage, are built to R2000
specification; this does require a 'sealed' vapour barrier house with
extensive use of sealants around all interior wall apertures. That type of
construction therefore requires an air/heat exchanger system which runs
continuously using AC mains and also careful additional ventilation of
bathrooms and cooking areas. Both my daughters houses each about 1500 sq.
feet per one floor plus a 'full basement' are built to this standard are
electrically heated and are very economical and comfortable.
Efficiencies of up to 80% heat recovery are claimed for the air/heat
exchangers but personally I doubt if that is true over a wide range of
temperatures. Not having an air exchanger in this older more 'leaky' and
less efficient house am not familiar with their operation in detail. They
do
produce condensate which is drained away by a tube and do need cleaning of
the filters and heat exchanger core fairly often.. (How much water vapour
does a human breathes out during a typical night? A litre or two?
By the way, misunderstandings persists about not allowing the house
humidity
to get into the outer walls of older homes. Consequently one hears a lot
of
nonsense about 'Not being able to keep paint on my house", among older
folks
who built houses in the older traditional way. As to why paint blisters
and
peels on the outside lapboards of a painted house. What's happening is
that
without vapour barriers and or adequate ventilation moisture condenses as
it
meets the cold 'within' the exterior walls and then pushes the paint off!
Houses finished with permeable stain permit that moisture, some will
always
occur, to 'breathe' out through the walls. This approach has worked for us
in the two houses we built and have lived in ourselves since 1960. Some
older houses that have been covered over with nice looking? but
impermeable
siding, such as vinyl, have suffered some rot within the walls! My
neighbour
had to replace most of one end wall of his less than 25 year old house!

As to why paint blisters and
peels on the outside lapboards of a painted house. What's happening is that
without vapour barriers and or adequate ventilation moisture condenses as
it
meets the cold 'within' the exterior walls and then pushes the paint off!
Houses finished with permeable stain permit that moisture, some will always
occur, to 'breathe' out through the walls.
A lot of issues here which I'm not qualified to argue about, but all paint
allows the passage of water vapour, while hopefully resisting water
droplets. Some figures were posted here a while back which suggested that
surface coatings offer virtually no resistance to vapour. I wonder whether
paint would peel off new lapboards as easily.
I think wood just deteriorates with age and becomes porous to the point
where it cannot support a coating.

"stuart noble" wrote in message
...

As to why paint blisters and
peels on the outside lapboards of a painted house. What's happening is
that
without vapour barriers and or adequate ventilation moisture condenses as
it
meets the cold 'within' the exterior walls and then pushes the paint off!
Houses finished with permeable stain permit that moisture, some will
always
occur, to 'breathe' out through the walls.

A lot of issues here which I'm not qualified to argue about, but all paint
allows the passage of water vapour, while hopefully resisting water
droplets. Some figures were posted here a while back which suggested that
surface coatings offer virtually no resistance to vapour. I wonder whether
paint would peel off new lapboards as easily.
I think wood just deteriorates with age and becomes porous to the point
where it cannot support a coating.

Oil based paint on bedroom ceilings will certainly act as a vapour barrier.
Not a full one, but will certainly help.

Terry wrote:

Another problem that can arise with very high levels of insulation and a
well sealed house, is large amounts of condensation.
In Scandinavian new builds I've seen this has been specially catered for.



Very interesting stuff, but of course in teh UK we don't get that much
ultra cold waeather, and teh cost benefit of such a system as described
below is not as great, if indeed it exists at all.

I certainly agree that hermetic sealing with heat exchange makes sense
if the temperature outside is going down to -25C or lower, but n ts
contry I am not conviced that the capital cost of that plus such
extremely high levels of inulation and sealing is justifed on either
straight economic or enegy saving basis: It does take a lot of energy to
make the materials of such a house.

I keep harking back to teh mediaeval castle, with a kitchen at the base
running chimneys up gians flues through teh walls to living quarters above.

The ultimate eco house probably has huge thick walls of simply earth,
and ventilation via long shafts that run next to flues so a natural heat
exchange would occur.




Well, sort of. But ..............
Here in Canada with longer colder winters (and often heat leaching winds!)
higher values of the insulation reduce heat loss and therefore the cost of
heating ones home. Since the energy cost increases of the 1970/80s etc. much
thicker insulation has been the 'standard'. Most wood frame houses now have
6 inch wooden stud outer walls filled with insulation and/or sheeted with
foam boards, older homes 4 inch.
But it is the 'vapour barrier' on the warm side of the insulation, whatever
type and thickness it is, that is important. It prevents the warm air from
seeping out into the outer walls and ceilings. Warm air is moist; when it
cools down the moisture in it condenses into water and can cause rot, mould,
damp/wet insulation and even condensation and water droplets in the attic.
(Saw one roof where every nail in the loft/attic was rusty!) same thing, on
a smaller scale, as occasionally happens in large stadia.during a
temperature change. i.e. "It rains indoors".
From time to time our National Government has provided incentives to
increase insulation values, typically and easily by adding several
additional inches to ceilings. Often easy to do using 'blown in' insulation.
But emphasis is always on proper installation, adding to and not blocking
off attic air circulation vents and stressing the use of proper vapour
barriers and or/sealing leakage up into the roof space.
An improper or missing vapour barrier in the ceilings and no attic
ventilation can spell expensive major problems. See damp attics and peeling
painted trim! One guy had 'mushrooms' (fungus) growing up there!
Most new Canadian houses now to qualify for mortgage, are built to R2000
specification; this does require a 'sealed' vapour barrier house with
extensive use of sealants around all interior wall apertures. That type of
construction therefore requires an air/heat exchanger system which runs
continuously using AC mains and also careful additional ventilation of
bathrooms and cooking areas. Both my daughters houses each about 1500 sq.
feet per one floor plus a 'full basement' are built to this standard are
electrically heated and are very economical and comfortable.
Efficiencies of up to 80% heat recovery are claimed for the air/heat
exchangers but personally I doubt if that is true over a wide range of
temperatures. Not having an air exchanger in this older more 'leaky' and
less efficient house am not familiar with their operation in detail. They do
produce condensate which is drained away by a tube and do need cleaning of
the filters and heat exchanger core fairly often.. (How much water vapour
does a human breathes out during a typical night? A litre or two?
By the way, misunderstandings persists about not allowing the house humidity
to get into the outer walls of older homes. Consequently one hears a lot of
nonsense about 'Not being able to keep paint on my house", among older folks
who built houses in the older traditional way. As to why paint blisters and
peels on the outside lapboards of a painted house. What's happening is that
without vapour barriers and or adequate ventilation moisture condenses as it
meets the cold 'within' the exterior walls and then pushes the paint off!
Houses finished with permeable stain permit that moisture, some will always
occur, to 'breathe' out through the walls. This approach has worked for us
in the two houses we built and have lived in ourselves since 1960. Some
older houses that have been covered over with nice looking? but impermeable
siding, such as vinyl, have suffered some rot within the walls! My neighbour
had to replace most of one end wall of his less than 25 year old house!

IMM wrote:

"Terry" wrote in message
. ..

Another problem that can arise with very high levels of insulation and a
well sealed house, is large amounts of condensation.
In Scandinavian new builds I've seen this has been specially catered

for.


Well, sort of. But ..............
Here in Canada with longer colder winters (and often heat leaching winds!)
higher values of the insulation reduce heat loss and therefore the cost of
heating ones home. Since the energy cost increases of the 1970/80s etc.

much

thicker insulation has been the 'standard'. Most wood frame houses now

have

6 inch wooden stud outer walls filled with insulation and/or sheeted with
foam boards, older homes 4 inch.
But it is the 'vapour barrier' on the warm side of the insulation,

whatever

type and thickness it is, that is important. It prevents the warm air from
seeping out into the outer walls and ceilings. Warm air is moist; when it
cools down the moisture in it condenses into water and can cause rot,

mould,

damp/wet insulation and even condensation and water droplets in the attic.


It also makes the house air-tight reducing much heat loss in winter, and
gain in the summer. The Canadians have the R2000 standard, which is one the
most advanced in the world, if not the most. The Canadians, say "build
tight, ventilate right".

Yes, but the whole point that you ALWAYS fail to realise is that cost
benefit analyse comes up with different answers for different climates.

In the Mediterranean and indeed in most tropical places, its well known
that insulation is pretty useless unless you also install air
conditioning, and its better to rely simply on shade (overhanging eaves)
and a lot of mass to average out diurnal temperature variations.

Mediterranean houses seem to have rooves of triple layers of tiles
cemented together, and concrete without insulation at all is the
preferred wall material - or simple blockwork. Timber house get
insufferably hot.

Yet in scandinavia, timer with massive insulation is the simple cheap
way to achieve warmth in winter.

One size fits all is your mentality John, and its an ideological
disaster everywhere its been applied.

"The Natural Philosopher" wrote in message
...
IMM wrote:

"Terry" wrote in message
. ..

Another problem that can arise with very high levels of insulation and
a
well sealed house, is large amounts of condensation.
In Scandinavian new builds I've seen this has been specially catered

for.


Well, sort of. But ..............
Here in Canada with longer colder winters (and often heat leaching
winds!)
higher values of the insulation reduce heat loss and therefore the cost
of
heating ones home. Since the energy cost increases of the 1970/80s etc.

much

thicker insulation has been the 'standard'. Most wood frame houses now

have

6 inch wooden stud outer walls filled with insulation and/or sheeted
with
foam boards, older homes 4 inch.
But it is the 'vapour barrier' on the warm side of the insulation,

whatever

type and thickness it is, that is important. It prevents the warm air
from
seeping out into the outer walls and ceilings. Warm air is moist; when
it
cools down the moisture in it condenses into water and can cause rot,

mould,

damp/wet insulation and even condensation and water droplets in the
attic.


It also makes the house air-tight reducing much heat loss in winter, and
gain in the summer. The Canadians have the R2000 standard, which is one
the
most advanced in the world, if not the most. The Canadians, say "build
tight, ventilate right".

Yes, but the whole point that you ALWAYS fail to realise is that cost
benefit analyse comes up with different answers for different climates.

In the Mediterranean and indeed in
most tropical places, its well known
that insulation is pretty useless unless
you also install air conditioning,

What codswallop!!! Look what they do in Florida.

On Tue, 24 Aug 2004 17:43:25 +0100, "stuart noble"
wrote:


As to why paint blisters and
peels on the outside lapboards of a painted house. What's happening is that
without vapour barriers and or adequate ventilation moisture condenses as
it
meets the cold 'within' the exterior walls and then pushes the paint off!
Houses finished with permeable stain permit that moisture, some will always
occur, to 'breathe' out through the walls.
A lot of issues here which I'm not qualified to argue about, but all paint
allows the passage of water vapour, while hopefully resisting water
droplets. Some figures were posted here a while back which suggested that
surface coatings offer virtually no resistance to vapour. I wonder whether
paint would peel off new lapboards as easily.

Hi,

The problem with damp painted wood is that when the sun hits it the
water may not escape through the paint fast enough and it gets almost
steamed off

I think wood just deteriorates with age and becomes porous to the point
where it cannot support a coating.

No, it won't change if it's protected by a coating, unless it's
rotting away.

cheers,
Pete.

"The Natural Philosopher" wrote in message
...
Terry wrote:

Another problem that can arise with
very high levels of insulation and a
well sealed house, is large amounts
of condensation.

Correct ventilation cures that.

Very interesting stuff, but of course
in teh UK we don't get that much
ultra cold waeather, and teh cost
benefit of such a system as described
below is not as great, if indeed it exists at all.

What tripe! Look at what Gorki Deveci has been doing in the UK.

I keep harking back to teh mediaeval
castle,

That is because you are ancient.

IMM wrote:

"The Natural Philosopher" wrote in message
Yes, but the whole point that you ALWAYS fail to realise is that cost
benefit analyse comes up with different answers for different climates.

In the Mediterranean and indeed in
most tropical places, its well known
that insulation is pretty useless unless
you also install air conditioning,


What codswallop!!! Look what they do in Florida.

You mean build timber frame houses with insulation, dry lining and loads
of air con?



--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
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| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

Terry wrote:

Another problem that can arise with very high levels of insulation and a
well sealed house, is large amounts of condensation.
In Scandinavian new builds I've seen this has been specially catered for.


Well, sort of. But ..............
Here in Canada with longer colder winters (and often heat leaching winds!)
higher values of the insulation reduce heat loss and therefore the cost of
heating ones home. Since the energy cost increases of the 1970/80s etc. much
thicker insulation has been the 'standard'. Most wood frame houses now have
6 inch wooden stud outer walls filled with insulation and/or sheeted with
foam boards, older homes 4 inch.
snip
Efficiencies of up to 80% heat recovery are claimed for the air/heat
exchangers but personally I doubt if that is true over a wide range of
temperatures. Not having an air exchanger in this older more 'leaky' and
less efficient house am not familiar with their operation in detail. They do
produce condensate which is drained away by a tube and do need cleaning of
the filters and heat exchanger core fairly often.. (How much water vapour
does a human breathes out during a typical night? A litre or two?

The air coming out of the lungs is at 37C, 100% humidity.
(the air coming out of the mouth may be a hair under this)
This works out at 40mmHg, or maybe 1/20th of the atmosphere coming
out.
At 15l/min, that's .8l/min of water vapour, or 384l/night.
As water, that's about 200ml or so.

However, it's only reasonable to insulate to the appropriate level.
Canada gets a mite chillier than the UK.
Insulating over what you need doesn't gain you anything, it just means
you have to do extra cooling.

"Ian Stirling" wrote in message
...
Terry wrote:

Another problem that can arise with very high levels of insulation and
a
well sealed house, is large amounts of condensation.
In Scandinavian new builds I've seen this has been specially catered
for.


Well, sort of. But ..............
Here in Canada with longer colder winters (and often heat leaching
winds!)
higher values of the insulation reduce heat loss and therefore the cost
of
heating ones home. Since the energy cost increases of the 1970/80s etc.
much
thicker insulation has been the 'standard'. Most wood frame houses now
have
6 inch wooden stud outer walls filled with insulation and/or sheeted
with
foam boards, older homes 4 inch.
snip
Efficiencies of up to 80% heat recovery are claimed for the air/heat
exchangers but personally I doubt if that is true over a wide range of
temperatures. Not having an air exchanger in this older more 'leaky' and
less efficient house am not familiar with their operation in detail.
They do
produce condensate which is drained away by a tube and do need cleaning
of
the filters and heat exchanger core fairly often.. (How much water
vapour
does a human breathes out during a typical night? A litre or two?

The air coming out of the lungs is at 37C, 100% humidity.
(the air coming out of the mouth may be a hair under this)
This works out at 40mmHg, or maybe 1/20th of the atmosphere coming
out.
At 15l/min, that's .8l/min of water vapour, or 384l/night.
As water, that's about 200ml or so.

However, it's only reasonable to insulate to the appropriate level.
Canada gets a mite chillier than the UK.
Insulating over what you need doesn't gain you anything, it just means
you have to do extra cooling.

What tripe!!!! Do some reading. Find out, don't make it up.

"John Rumm" wrote in message
...
IMM wrote:

"The Natural Philosopher" wrote in message
Yes, but the whole point that you ALWAYS fail to realise is that cost
benefit analyse comes up with different answers for different climates.

In the Mediterranean and indeed in
most tropical places, its well known
that insulation is pretty useless unless
you also install air conditioning,

What codswallop!!! Look what they do in Florida.

You mean build timber frame houses with insulation,

Yes.

On Thu, 26 Aug 2004 00:07:44 +0100, "IMM" wrote:


"John Rumm" wrote in message
...
IMM wrote:

"The Natural Philosopher" wrote in message
Yes, but the whole point that you ALWAYS fail to realise is that cost
benefit analyse comes up with different answers for different climates.

In the Mediterranean and indeed in
most tropical places, its well known
that insulation is pretty useless unless
you also install air conditioning,

What codswallop!!! Look what they do in Florida.

You mean build timber frame houses with insulation,

Yes.


.... and repeat after me three times "We're not in Kansas any more,
Toto"

Do you tango in ruby slippers?


..andy

To email, substitute .nospam with .gl

"Andy Hall" wrote in message
...

Do you tango in ruby slippers?

No. Do you?

IMM wrote:

"The Natural Philosopher" wrote in message
...

IMM wrote:


"Terry" wrote in message
om...


Another problem that can arise with very high levels of insulation and

a

well sealed house, is large amounts of condensation.
In Scandinavian new builds I've seen this has been specially catered

for.


Well, sort of. But ..............
Here in Canada with longer colder winters (and often heat leaching

winds!)

higher values of the insulation reduce heat loss and therefore the cost

of

heating ones home. Since the energy cost increases of the 1970/80s etc.

much


thicker insulation has been the 'standard'. Most wood frame houses now

have


6 inch wooden stud outer walls filled with insulation and/or sheeted

with

foam boards, older homes 4 inch.
But it is the 'vapour barrier' on the warm side of the insulation,

whatever


type and thickness it is, that is important. It prevents the warm air

from

seeping out into the outer walls and ceilings. Warm air is moist; when

it

cools down the moisture in it condenses into water and can cause rot,

mould,


damp/wet insulation and even condensation and water droplets in the

attic.


It also makes the house air-tight reducing much heat loss in winter, and
gain in the summer. The Canadians have the R2000 standard, which is one

the

most advanced in the world, if not the most. The Canadians, say "build
tight, ventilate right".


Yes, but the whole point that you ALWAYS fail to realise is that cost
benefit analyse comes up with different answers for different climates.

In the Mediterranean and indeed in
most tropical places, its well known
that insulation is pretty useless unless
you also install air conditioning,


What codswallop!!! Look what they do in Florida.


Install air conditioning?

John Rumm wrote:

IMM wrote:

"The Natural Philosopher" wrote in message

Yes, but the whole point that you ALWAYS fail to realise is that cost
benefit analyse comes up with different answers for different climates.

In the Mediterranean and indeed in
most tropical places, its well known
that insulation is pretty useless unless
you also install air conditioning,



What codswallop!!! Look what they do in Florida.


You mean build timber frame houses with insulation, dry lining and loads
of air con?



Precisely.

IMM wrote:

"John Rumm" wrote in message
...

IMM wrote:


"The Natural Philosopher" wrote in message

Yes, but the whole point that you ALWAYS fail to realise is that cost
benefit analyse comes up with different answers for different climates.

In the Mediterranean and indeed in
most tropical places, its well known
that insulation is pretty useless unless
you also install air conditioning,

What codswallop!!! Look what they do in Florida.

You mean build timber frame houses with insulation,


Yes.


As I said,

"insulation is pretty useless UNLESS you also install air conditioning"

So IMM has completely contradicted himself, by first of all claiming
that is codswallop, secondly pointing us to Florida to support this
thesis, and finally confirming that what they do there is *precisely*
what I said in the first place, and which he contradicted.

If any more clear indication of the egregious IMM's 'prejudice over
knowledge' is needed, I don't know what it is.

As well as blatant hypocrisy.

IMM wrote:
snip What tripe!!!! Do some reading. Find out, don't make it up.

Could you explain in small words - I'm stupid you see.

If your house is insulated well enough that you need ventilation to
keep it cool even on the coldest night, what benefit do you gain by doubling
the insulation?

"The Natural Philosopher" wrote in message
...
IMM wrote:

"John Rumm" wrote in message
...

IMM wrote:


"The Natural Philosopher" wrote in message

Yes, but the whole point that you ALWAYS fail to realise is that cost
benefit analyse comes up with different answers for different
climates.

In the Mediterranean and indeed in
most tropical places, its well known
that insulation is pretty useless unless
you also install air conditioning,

What codswallop!!! Look what they do in Florida.

You mean build timber frame houses with insulation,

Yes.

As I said,

"insulation is pretty useless UNLESS you also install air conditioning"

So IMM has completely contradicted himself,

I never.

by first of all claiming
that is codswallop,

It was.

secondly pointing us to Florida to support this
thesis,

And it did.

and finally confirming that what they do there is *precisely*
what I said in the first place,

You never.

and which he contradicted.

I never.

If any more clear indication of the egregious IMM's 'prejudice over
knowledge' is needed, I don't know what it is.

As well as blatant hypocrisy.

It is obvious the snots do not teach common sense.

The Natural Philosopher wrote:

So IMM has completely contradicted himself, by first of all claiming
that is codswallop, secondly pointing us to Florida to support this
thesis, and finally confirming that what they do there is *precisely*
what I said in the first place, and which he contradicted.

Give him enough rope ;-)


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

IMM wrote:


I never.

It was.

And it did.

You never.

I never.

Aha - I think we have seen this end game before...

The "Night is Day" assertion, followed by

It is obvious the snots do not teach common sense.

Let's insult someone and hope they don't spot that he has lost the plot.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

Ian Stirling wrote:


Could you explain in small words - I'm stupid you see.

If your house is insulated well enough that you need ventilation to
keep it cool even on the coldest night, what benefit do you gain by doubling
the insulation?

Let me guess: "Twice the insulation, a win win situation, simple really"

Heat control is not a problem - since there will be so little space left
inside you house that you need to sleep in the garden anyway...

(assuming you are allowed a garden in johnny six chins prescott's vision
of 30/acre "affordable" housing) ;-)

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

"John Rumm" wrote in message
...
IMM wrote:


I never.

It was.

And it did.

You never.

I never.

Aha - I think we have seen this end game before...

The "Night is Day" assertion, followed by

It is obvious the snots do not teach common sense.

Let's insult someone and hope they don't spot that he has lost the plot.

Do you mean the snots do teach common sense?

"John Rumm" wrote in message
...

Let me guess: "Twice the insulation, a win win situation, simple really"

Some sense here. Encouraging.

Heat control is not a problem - since there will be so little space left
inside you house that you need to sleep in the garden anyway...

...what a bummer, back to normal.

snip

John Rumm wrote:
The Natural Philosopher wrote:

So IMM has completely contradicted himself, by first of all claiming
that is codswallop, secondly pointing us to Florida to support this
thesis, and finally confirming that what they do there is *precisely*
what I said in the first place, and which he contradicted.

Give him enough rope ;-)

I've got a spare couple of dozen yards.
Does anyone know his postal address?

"Ian Stirling" wrote in message
...
John Rumm wrote:
The Natural Philosopher wrote:

So IMM has completely contradicted himself, by first of all claiming
that is codswallop, secondly pointing us to Florida to support this
thesis, and finally confirming that what they do there is *precisely*
what I said in the first place, and which he contradicted.

Give him enough rope ;-)

I've got a spare couple of dozen yards.
Does anyone know his postal address?

Given up sailing there, sailor.

Ian Stirling wrote:

IMM wrote:
snip What tripe!!!! Do some reading. Find out, don't make it up.

Could you explain in small words - I'm stupid you see.

If your house is insulated well enough that you need ventilation to
keep it cool even on the coldest night, what benefit do you gain by doubling
the insulation?

Free Moths?

John Rumm wrote:

Ian Stirling wrote:


Could you explain in small words - I'm stupid you see.

If your house is insulated well enough that you need ventilation to
keep it cool even on the coldest night, what benefit do you gain by
doubling
the insulation?


Let me guess: "Twice the insulation, a win win situation, simple really"

Heat control is not a problem - since there will be so little space left
inside you house that you need to sleep in the garden anyway...

(assuming you are allowed a garden in johnny six chins prescott's vision
of 30/acre "affordable" housing) ;-)

It occurs to me that the ultimate extesnion of IMM and Prescotts
Socialist Vishzuns is a sort of super prison where we all live in rabbit
hutch cells...and get time in the laundry for good behaviour..

What? Its like that already? Blimey. So it is.

IMM wrote:

"John Rumm" wrote in message
...

IMM wrote:



I never.

It was.

And it did.

You never.

I never.

Aha - I think we have seen this end game before...

The "Night is Day" assertion, followed by


It is obvious the snots do not teach common sense.

Let's insult someone and hope they don't spot that he has lost the plot.


Do you mean the snots do teach common sense?


No, they are just born with it.

Honestly, what DID you think the silver spoon was FOR?