Mark T.B. Carroll wrote:
The Natural Philosopher writes:

[ plenty of interesting stuff ]

I was wondering, is there any real value to these powdered paint
additives that are sold as imbuing the paint with insulating properties?

FWIW with windows I'm wondering how regular heavy curtains compare to
these honeycomb shades and blinds with the air cells in them that sit
actually in the frame.


Not sure about what you mean there..
...but there is a definite case for having better insulation when you
don't need the light.

However, it is not a huge factor either way.


-- Mark

Tony Bryer wrote:
On Wed, 17 Jan 2007 16:38:06 +0000 The Natural Philosopher wrote :
I don't think so.

I have been watching the digital stat this winter..a sunny clear
day as opposed to a dull one nets only about 1-2C rise in the room.
And thats from the solar systems best 'radiator'

I guess the reason why we put on anoraks is to stop our bodies
losing heat by radiation eh?

multi layer things like coats and jackets that trap air in spaces
are known to be better than one thick layer..curtains when lined
are simply an example of the same.

Yes, but curtains, mine away, are not trapping air behind them to any
extent. You've got gaps at the cill and at rail level a continuous gap
(with most curtain rails anyway).


We have to have the rail 3" away because the curtains are gathered +-3"
at the top. You can or course use a pelmet although those have gone out
of fashion. They should overlap the window boards..and fall against them.

Of course they are not hermetic seals, but they are trappers of air to a
large extent..they must be or I would not see remarkable differences
between windows with curtains drawn, and not.

Alex Selby wrote:
The Natural Philosopher wrote:
...
Its very hard to see why double glazing is so insisted on.

...

Let's say we have two windows totalling 2.5 sq meters. At a U value of
5..so thats just 8% of the total heatloss from the room. A GOOD DG
unit should more than halve that..netting us a 4% gain, or ariound
17.5 watts average, and annualized around 155KWh..say at 10p per
unit..£15 a year gain.For probably about £1500 outlay. So a 1% ROI.


Great post. It's really good to cut through the hype with some
calculations, but I don't totally agree with all of your figures.

In the above case, you've assumed an average temperature difference of
5C, but 10C is nearer the mark. (This improves the benefit of insulation
but doesn't alter the calculation of the benefit of turning your heating
down by a degree.)


Agreed. I found te met office stats.

You've assumed a cost of DG of £600/m^2, but I've just been quoted for a
job at £270/m^2.

Fair enough. That was a stab in the dark. I reckon that £500 a window
installed with frames is an average sort of figure. And the average
window is about a square meter or so,



You've assumed that you are replacing a fairly good existing SG unit.
This may be the case, but if you want to understand why DG is insisted
on then what about the case of replacing a drafty SG unit at the end of
its life, or the case of a new building. In these cases you need to
subtract from £270 the cost per m^2 of SG to make a proper comparison.

Indeed. I thought I had made that point...that unless you had reason to
replace the windows anyway, it wasn't a runner. If you put very cheap
modern sealing strip round and old wood casement I reckon you rep 70-80%
of the benefits of DG at about 1/0th the cost or less.


If you are installing new windows, apart from a severe attack of
aesthetics, there is no reason NOT to install DG, the opportunity cost
is low enough.

I was really coming at this from the point of someone who might be
(genuinely) concerned about energy, and cost benefit on heating, and
pointing out that received wisdom is largely driven by DG marketing and
lack of hard information.

I.e. my conclusins can be stated two ways

'DG windows are 2-3 times as good as single glazed'

'installing DG windows will save you at best 2% of your energy bill,
(all other things being equal)'

Both are reasonably 'true' statements.


On the other hand, you've assumed 10p per unit. This should be a lot
less if you used gas, which reduces the ROI.

Its about 3p .. think we worked that out..thats why in the end I
switched to oil burned at 50% efficiency..except where talking about CFL
lamps.

So the minimum ROI is
10*.3*2.5/1000*365*24/270 = 2.4%
(assumes you're replacing a perfectly good SG unit and heating with gas
at 3p per unit).


The cheaper the fuel the LESS the ROI is..so I am not sure how you got
more..

To work out the maximum ROI we need to know the cost of SG, which I
don't. Taking it to be £135/m^2 we get
10*.1*2.5/1000*365*24/135 = 16%
(assumes you're building from new or the existing SG unit needs
replacing; assumes heating with electricity).


Yup. I never was actually talking about installing SG from new..you only
do that - as we did - out of an attack of aesthetics. Double glazing
cannot be incorporated into lead lights and applied 'glazing bars' looks
crap. So almost certainly your SG units will be more expensive, cos they
are hand made specials.


There are also benefits in terms of quality of heat. If you just replace
heat lost from the windows with central heating then you get
temperature differentials - colder nearer the floor than at head level
etc - which is not as snug as uniform heat (in my opinion).

And there are benefits of DG in terms of extra sound insulation too.


Actually, we have high quality sealed SG here, installed from new, and I
have to say the noise reductions is similar. It seems to be the sealing
that is the key, rather than the DG.


Alex

I am not in general trying to say what you seem to think I am..that we
shouldn't be putting DG or even TG in new builds. Of course we should
bne. The *opportunity* cost is low enough, and the gains significant
enough..to make it worth while.

My real thrust was at those people who have bought a nice solid
(literally) walled Victorian property, find it chilly, and costing a lot
to make snug, and instantly go out and fit DG.

The real point is that after whacking in loft insulation and SEALING it
against draughts in the loft,and putting weatherstrip on the windows and
doors, the very next think is to line the walls.

And possibly the floor.

There are HUGE potential gains to be had here, from not all that much
thickness of insulation. 6" of rockwool or celotex is easy to install
under a suspended floor for example. 2" of celotex on the outside walls
is not going to break the bank. And you could be looking at 70% or more
improvement in energy and bills.

Once that is done, boiler efficiency is not so important, and there is
always a moot point as to how much MORE energy the new boiler takes to make.

Attention to electrical stuff is fairly trivial in terms of planet
saving. Far better gains can be had by switching off huge amounts of
public lighting between say 2 am and 6 a.m. However CFL bulbs are cheap
enough to pay for themselves in a few months..I use them because they
don't blow up every five minutes.

Likewise teenagers who spend 10-15 minutes in the shower are not saving
water or energy vis a vis a bath, either.

The Natural Philosopher wrote:

My real thrust was at those people who have bought a nice solid
(literally) walled Victorian property, find it chilly, and costing a lot
to make snug, and instantly go out and fit DG.

snip!

I'll concur with the gist of this message. In our case, our (modern)
house already had insulation in the cavity (and I'm not going round
adding an inside skin of more insulation and plasterboard). I'd already
topped up the loft insulation to about 12-14". It's a solid concrete
floor. The *last* thing to do was the DG.

That was done primarily to improve comfort levels (less condensation,
less draughts coming off the cold SG pane, more even temperatures) and
the SG windows needed maintenance....

J

The Natural Philosopher wrote:
Alex Selby wrote:
The Natural Philosopher wrote:

If you are installing new windows, apart from a severe attack of
aesthetics, there is no reason NOT to install DG, the opportunity cost
is low enough.

I was really coming at this from the point of someone who might be
(genuinely) concerned about energy, and cost benefit on heating, and
pointing out that received wisdom is largely driven by DG marketing and
lack of hard information.

Yup. I never was actually talking about installing SG from new..you only
do that - as we did - out of an attack of aesthetics. Double glazing
cannot be incorporated into lead lights and applied 'glazing bars' looks
crap. So almost certainly your SG units will be more expensive, cos they
are hand made specials.

I think there is some confusion here btween dg and upvc. The listed
problems apply to upvc, but no such issues apply to dg. Leaded windows
can be dg no problem, and oak dg does not have the butt ugly factor of
upvc.


NT

The Natural Philosopher wrote:

When hanging naturally our curtains are about 1cm thick. I can't begin
to consider that is worse than a 12mm gap between two pieces of glass.

Over our patio door/window we have net curtains and double-lined thick
curtains. To prevent condensation due to the 'reverse chimney effect'
we also use a sammy snake across the bottom of the curtains, when
drawn for the evening.

One cold night last winter, 0degC outside, I placed our weather
station's outside thermometer betweem the window and the net curtain,
and sat back to watch.

Eventually, the inside thermometer was reading 22degC, but the one
behind the curtains wasn't far off 0degC, about 2 IIRC.

Those curtains were - and are - doing a fine job.

--

Frank

The Natural Philosopher wrote:
....
So the minimum ROI is
10*.3*2.5/1000*365*24/270 = 2.4%
(assumes you're replacing a perfectly good SG unit and heating with
gas at 3p per unit).


Typo in the above: it should say .03 not .3. The answer is still 2.4%.


The cheaper the fuel the LESS the ROI is..so I am not sure how you got
more..

Because there are three error factors increasing the ROI from the 1% you
originally calculated and only one (the fuel cost) reducing it. (i) temp
diff, (ii) cost of DG, (iii) you said 8% of the heat loss is through the
window when you should have said 14% = 5*2.5/(3.5*25). The net effect
of all these corrections makes it a 2.4% ROI as a minimum case.


To work out the maximum ROI we need to know the cost of SG, which I
don't. Taking it to be £135/m^2 we get
10*.1*2.5/1000*365*24/135 = 16%
(assumes you're building from new or the existing SG unit needs
replacing; assumes heating with electricity).


Yup. I never was actually talking about installing SG from new..you only
do that - as we did - out of an attack of aesthetics. Double glazing
cannot be incorporated into lead lights and applied 'glazing bars' looks
crap. So almost certainly your SG units will be more expensive, cos they
are hand made specials.

In that case the benefit of DG could be even more than 16% of course.



There are also benefits in terms of quality of heat. If you just
replace heat lost from the windows with central heating then you get
temperature differentials - colder nearer the floor than at head level
etc - which is not as snug as uniform heat (in my opinion).

And there are benefits of DG in terms of extra sound insulation too.


Actually, we have high quality sealed SG here, installed from new, and I
have to say the noise reductions is similar. It seems to be the sealing
that is the key, rather than the DG.

Fair enough. If you are comparing with high quality SG which you already
have and are not costing then of course the benefits of DG will be smaller.



Alex

I am not in general trying to say what you seem to think I am..that we
shouldn't be putting DG or even TG in new builds. Of course we should
bne. The *opportunity* cost is low enough, and the gains significant
enough..to make it worth while.

But you said "it's very hard to see why double glazing is so insisted
on". I was just trying to explain why I think it makes a lot of sense in
many cases.


My real thrust was at those people who have bought a nice solid
(literally) walled Victorian property, find it chilly, and costing a lot
to make snug, and instantly go out and fit DG.

The real point is that after whacking in loft insulation and SEALING it
against draughts in the loft,and putting weatherstrip on the windows and
doors, the very next think is to line the walls.

And possibly the floor.

Yes yes, I am completely sold on all that. You are preaching to the
converted. I was just talking about DG and I wanted to fix the calculation.


There are HUGE potential gains to be had here, from not all that much
thickness of insulation. 6" of rockwool or celotex is easy to install
under a suspended floor for example. 2" of celotex on the outside walls
is not going to break the bank. And you could be looking at 70% or more
improvement in energy and bills.

Once that is done, boiler efficiency is not so important, and there is
always a moot point as to how much MORE energy the new boiler takes to
make.

Attention to electrical stuff is fairly trivial in terms of planet
saving. Far better gains can be had by switching off huge amounts of
public lighting between say 2 am and 6 a.m. However CFL bulbs are cheap
enough to pay for themselves in a few months..I use them because they
don't blow up every five minutes.

Likewise teenagers who spend 10-15 minutes in the shower are not saving
water or energy vis a vis a bath, either.


Alex

Jonathan Tong wrote:

The Natural Philosopher wrote:

My real thrust was at those people who have bought a nice solid
(literally) walled Victorian property, find it chilly, and costing a
lot to make snug, and instantly go out and fit DG.

snip!

I'll concur with the gist of this message. In our case, our (modern)
house already had insulation in the cavity (and I'm not going round
adding an inside skin of more insulation and plasterboard). I'd already
topped up the loft insulation to about 12-14". It's a solid concrete
floor. The *last* thing to do was the DG.

That was done primarily to improve comfort levels (less condensation,
less draughts coming off the cold SG pane, more even temperatures) and
the SG windows needed maintenance....

J
In which case I absolutely agree with you. If the framea are rotten and
draughty, They need replacing and DG is the way yo go.

wrote:
The Natural Philosopher wrote:
Alex Selby wrote:
The Natural Philosopher wrote:

If you are installing new windows, apart from a severe attack of
aesthetics, there is no reason NOT to install DG, the opportunity cost
is low enough.

I was really coming at this from the point of someone who might be
(genuinely) concerned about energy, and cost benefit on heating, and
pointing out that received wisdom is largely driven by DG marketing and
lack of hard information.

Yup. I never was actually talking about installing SG from new..you only
do that - as we did - out of an attack of aesthetics. Double glazing
cannot be incorporated into lead lights and applied 'glazing bars' looks
crap. So almost certainly your SG units will be more expensive, cos they
are hand made specials.

I think there is some confusion here btween dg and upvc. The listed
problems apply to upvc, but no such issues apply to dg. Leaded windows
can be dg no problem,

They cannot. Not true lead lights anyway. The frit sealing in DG panels
is about three times as wide as the lead glazing. and a 15mm wide panle
looks silly anyway in a leaded light. The only recourse is to apply fake
glazing bars, and they either look really odd from inside, or outside,
or if applied both sized, at an angle.



and oak dg does not have the butt ugly factor of
upvc.

Oak with DG is lovely, if the style suits..but as I say, if you want
real leads, DG is out.



NT

Frank Lee Speke-King wrote:
The Natural Philosopher wrote:

When hanging naturally our curtains are about 1cm thick. I can't begin
to consider that is worse than a 12mm gap between two pieces of glass.

Over our patio door/window we have net curtains and double-lined thick
curtains. To prevent condensation due to the 'reverse chimney effect'
we also use a sammy snake across the bottom of the curtains, when
drawn for the evening.

One cold night last winter, 0degC outside, I placed our weather
station's outside thermometer betweem the window and the net curtain,
and sat back to watch.

Eventually, the inside thermometer was reading 22degC, but the one
behind the curtains wasn't far off 0degC, about 2 IIRC.

Those curtains were - and are - doing a fine job.


Was that SG? if so and you had say -2 outside, that would put the
curtains at about 4:1 better than the SG..say around 1 or 1.2 U value.

About twice as good as DG.

The Natural Philosopher wrote:

Frank Lee Speke-King wrote:

One cold night last winter, 0degC outside, I placed our weather
station's outside thermometer betweem the window and the net curtain,
and sat back to watch.

Eventually, the inside thermometer was reading 22degC, but the one
behind the curtains wasn't far off 0degC, about 2 IIRC.

Those curtains were - and are - doing a fine job.

Was that SG? if so and you had say -2 outside, that would put the
curtains at about 4:1 better than the SG..say around 1 or 1.2 U value.

About twice as good as DG.

Aluminium patio door and window frame, about 8'w x 6'h, 1" air gap
between the DG panels.

--

Frank

The Natural Philosopher wrote:
wrote:

I think there is some confusion here btween dg and upvc. The listed
problems apply to upvc, but no such issues apply to dg. Leaded windows
can be dg no problem,

They cannot. Not true lead lights anyway. The frit sealing in DG panels
is about three times as wide as the lead glazing.

all that tells us is the design of dg you have in mind can't be done.

and a 15mm wide panle
looks silly anyway in a leaded light.

The ones I saw were much deeper than that and looked fine. They were
hardly noticeable.

The only recourse is to apply fake
glazing bars, and they either look really odd from inside, or outside,
or if applied both sized, at an angle.

those are like serving up a wimpy in place of beef steak au poivre.


and oak dg does not have the butt ugly factor of
upvc.

Oak with DG is lovely, if the style suits..but as I say, if you want
real leads, DG is out.

I've seen it done twice. There is no technical reason not to create
real leaded dg, but obviously the design is different to the popular
sealed panels, since leaded glass is not an airtight glazing surface.
DG does not inherently mean sealed, unsealed dg has been around for a
long time.

The thermal characteristics are not as good as the usual dg, since the
lead is so conductive and not airtight.


NT

Alex Selby wrote:
The Natural Philosopher wrote:

My real thrust was at those people who have bought a nice solid
(literally) walled Victorian property, find it chilly, and costing a
lot to make snug, and instantly go out and fit DG.

The real point is that after whacking in loft insulation and SEALING
it against draughts in the loft,and putting weatherstrip on the
windows and doors, the very next think is to line the walls.

And possibly the floor.

Yes yes, I am completely sold on all that. You are preaching to the
converted. I was just talking about DG and I wanted to fix the calculation.

Sorry I meant to say that more graciously. I think you do us a service
by illuminating these issues.

Alex

Frank Lee Speke-King wrote:
The Natural Philosopher wrote:

Frank Lee Speke-King wrote:

One cold night last winter, 0degC outside, I placed our weather
station's outside thermometer betweem the window and the net curtain,
and sat back to watch.

Eventually, the inside thermometer was reading 22degC, but the one
behind the curtains wasn't far off 0degC, about 2 IIRC.

Those curtains were - and are - doing a fine job.
Was that SG? if so and you had say -2 outside, that would put the
curtains at about 4:1 better than the SG..say around 1 or 1.2 U value.

About twice as good as DG.

Aluminium patio door and window frame, about 8'w x 6'h, 1" air gap
between the DG panels.

That is surprising..any gen on how cold it was outside?

Alex Selby wrote:
Alex Selby wrote:
The Natural Philosopher wrote:

My real thrust was at those people who have bought a nice solid
(literally) walled Victorian property, find it chilly, and costing a
lot to make snug, and instantly go out and fit DG.

The real point is that after whacking in loft insulation and SEALING
it against draughts in the loft,and putting weatherstrip on the
windows and doors, the very next think is to line the walls.

And possibly the floor.

Yes yes, I am completely sold on all that. You are preaching to the
converted. I was just talking about DG and I wanted to fix the
calculation.

Sorry I meant to say that more graciously. I think you do us a service
by illuminating these issues.


I don't do gracious meself anyway, so no problems

Alex

"The Natural Philosopher" wrote in message
...

The real point is that after whacking in loft insulation and SEALING it
against draughts in the loft...

You probably know but others might not...

It's very important to NOT to just wack some insulation between the rafters
or you risk a condensation problem and potential long term problems for the
roof structure. Lofts are generally designed to be ventilated spaces to
allow any moisture from the house to be removed.

If you want to put insulation between the rafters and seal the loft to
create a semi-warm storage space then you should consider going the whole
hog as you would for a loft conversion.....

Add batterns to the sides of the rafters to stop the insulation coming in
contact with the underside of the tiles/sarking and provide a 50mm
ventilation space. Install sufficient insulation between and below the
rafters (perhaps 150-200mm thick in total), then a correctly installed
vapour barrier to keep moisture away from the cold tiles/rafters. Add small
vents from the inside of the loft to the outside to allow any moisture in
the loft to get out. The next step would be to line with plasterboard but
that would probably make it a loft conversion in the eyes of building
control.

The alternative is to put insulation between the ceiling joists and retain
it as a cold roof. Seal gaps between the house and loft to keep moisture out
of the loft. Leave the gaps under the eaves open to ventilate the loft.
Insulate the loft hatch.

Colin









and putting weatherstrip on the windows and
doors, the very next think is to line the walls.




And possibly the floor.

There are HUGE potential gains to be had here, from not all that much
thickness of insulation. 6" of rockwool or celotex is easy to install
under a suspended floor for example. 2" of celotex on the outside walls
is not going to break the bank. And you could be looking at 70% or more
improvement in energy and bills.

Once that is done, boiler efficiency is not so important, and there is
always a moot point as to how much MORE energy the new boiler takes to
make.

Attention to electrical stuff is fairly trivial in terms of planet
saving. Far better gains can be had by switching off huge amounts of
public lighting between say 2 am and 6 a.m. However CFL bulbs are cheap
enough to pay for themselves in a few months..I use them because they
don't blow up every five minutes.

Likewise teenagers who spend 10-15 minutes in the shower are not saving
water or energy vis a vis a bath, either.

In message , at 09:34:12 on
Thu, 18 Jan 2007, The Natural Philosopher remarked:
Double glazing cannot be incorporated into lead lights and applied
'glazing bars' looks crap. So almost certainly your SG units will be
more expensive, cos they are hand made specials.

What you can do (and I have some DG patio doors, and about a third of
the other windows in my house like this) is make a double glazing unit
that has a traditional sheet of lead lights in between. This has the
added advantage that they are easier to clean, and it looks good too!
--
Roland Perry

The Natural Philosopher wrote:

Frank Lee Speke-King wrote:
The Natural Philosopher wrote:

Frank Lee Speke-King wrote:

One cold night last winter, 0degC outside, I placed our weather
station's outside thermometer betweem the window and the net curtain,
and sat back to watch.

Eventually, the inside thermometer was reading 22degC, but the one
behind the curtains wasn't far off 0degC, about 2 IIRC.

Those curtains were - and are - doing a fine job.
Was that SG? if so and you had say -2 outside, that would put the
curtains at about 4:1 better than the SG..say around 1 or 1.2 U value.

About twice as good as DG.

Aluminium patio door and window frame, about 8'w x 6'h, 1" air gap
between the DG panels.

That is surprising..any gen on how cold it was outside?

AFAICR it was something like -5 degC.

--

Frank

On 2007-01-20 18:28:42 +0000, Frank Lee Speke-King
said:


The Natural Philosopher wrote:

Frank Lee Speke-King wrote:

Aluminium patio door and window frame, about 8'w x 6'h, 1" air gap
between the DG panels.

That is surprising..any gen on how cold it was outside?

AFAICR it was something like -5 degC.

Fairly normal for Speke


I went to the airport there once. I think it involves John Lennon
these days for some reason - goodness knows why. There were tyre
marks on the top of the car factory (Ford I think it was) from the
aircraft. It made Ringway look sophisticated.

Roland Perry wrote:
In message , at 09:34:12 on
Thu, 18 Jan 2007, The Natural Philosopher remarked:
Double glazing cannot be incorporated into lead lights and applied
'glazing bars' looks crap. So almost certainly your SG units will be
more expensive, cos they are hand made specials.

What you can do (and I have some DG patio doors, and about a third of
the other windows in my house like this) is make a double glazing unit
that has a traditional sheet of lead lights in between. This has the
added advantage that they are easier to clean, and it looks good too!

That is actually a very good idea..like a triple glazed unit eh?

In message , at 01:11:11 on
Sun, 21 Jan 2007, The Natural Philosopher remarked:
What you can do (and I have some DG patio doors, and about a third
of the other windows in my house like this) is make a double glazing
unit that has a traditional sheet of lead lights in between. This has
the added advantage that they are easier to clean, and it looks good too!

That is actually a very good idea..like a triple glazed unit eh?

I suppose it has some of the characteristics of triple glazing, but
there's quite a small airgap between the inner or outer panes, and the
encapsulated leaded lights. What I don't know is whether that increases
or decreases the insulation factor.

Your recent posting regarding the relative irrelevance of DG as an
insulating device makes me feel happier about them than I was, so thanks
for that!
--
Roland Perry

On Sun, 21 Jan 2007 09:55:36 -0000, Roland Perry
wrote:

In message , at 01:11:11 on
Sun, 21 Jan 2007, The Natural Philosopher remarked:
What you can do (and I have some DG patio doors, and about a third
of the other windows in my house like this) is make a double glazing
unit that has a traditional sheet of lead lights in between. This has
the added advantage that they are easier to clean, and it looks good
too!

That is actually a very good idea..like a triple glazed unit eh?

I suppose it has some of the characteristics of triple glazing, but
there's quite a small airgap between the inner or outer panes, and the
encapsulated leaded lights. What I don't know is whether that increases
or decreases the insulation factor.

Your recent posting regarding the relative irrelevance of DG as an
insulating device makes me feel happier about them than I was, so thanks
for that!


Almost certainly increases it, less convection & two more surfaces ought
to outweigh the conductivity.

Roland Perry wrote:
In message , at 01:11:11 on
Sun, 21 Jan 2007, The Natural Philosopher remarked:
What you can do (and I have some DG patio doors, and about a third
of the other windows in my house like this) is make a double glazing
unit that has a traditional sheet of lead lights in between. This
has the added advantage that they are easier to clean, and it looks
good too!

That is actually a very good idea..like a triple glazed unit eh?

I suppose it has some of the characteristics of triple glazing, but
there's quite a small airgap between the inner or outer panes, and the
encapsulated leaded lights. What I don't know is whether that increases
or decreases the insulation factor.

Your recent posting regarding the relative irrelevance of DG as an
insulating device makes me feel happier about them than I was, so thanks
for that!


DG isn't so much irrelevant, as completely over-emphasised.

I am wholly in favour of it in new builds or upgrades, except where its
appearance simply won't cut the mustard.

Its the insistence that taking out perfectly good SG and replacing it
should be the *first* thing a homeowner does that gets my goat..whereas
damn thick curtains will achieve far more if the SG is draughtproof.
AND the total underemphasis on cavity wall insulation or dry lining
outer walls, and doing something about suspended wooden floors. Which
are, after the loft, and draughts, the dominant heat loss paths in older
houses.

Myl old hosuse had a convereted single rendred celcon block garage that
was converted by adding in 2" studs with rockwool and plasterboarding it
out. It wass one of the cosiest rooms in that house.

"The Natural Philosopher" wrote in message
...
I am wholly in favour of it in new builds or upgrades, except where its
appearance simply won't cut the mustard.

DG is almost compulsory for new builds to meet the regs. I believe the regs
specify U values for walls and windows that imply DG but I think they also
specify an overall U Value as an alternative method that might allow SG. Got
a feeling that SG windows might have to be small as a percentage of the
area..

CWatters wrote:
"The Natural Philosopher" wrote in message
...
I am wholly in favour of it in new builds or upgrades, except where its
appearance simply won't cut the mustard.

DG is almost compulsory for new builds to meet the regs. I believe the regs
specify U values for walls and windows that imply DG but I think they also
specify an overall U Value as an alternative method that might allow SG. Got
a feeling that SG windows might have to be small as a percentage of the
area..


Its cots me in 2000 about £250 to get a SAP rating calcualated for the
proposed build here. SG windows. They aren't large, but they aren;t
small either.

Essentially I had to go thicker on wall and roof insulation, thats all.

The Natural Philosopher wrote lots of really useful stuff,
and then this:
7/. One annual trip of 2000 miles by plane (at about 70mpg per
passenger)is peanuts compared with the 12,000 miles you do to commute to
your job at 45mpgh, or less in congestion..

OK, so for a family of four you have to multiply that up, (which you
don't for an equivalent car journey), and 2000 miles is the round-trip
so you "only" get to go 1000 miles away.

To be more realistic, a single holiday to (say) New York for a family of
four equates to an approx. total round trip of 8000 miles per passenger,
so 32,000 miles at 70mpg. So that's the equivalent fuel use of 16,000
miles in a 35mpg car, which is substantially more than I do in a year.

Simon.

simon wrote:
The Natural Philosopher wrote lots of really useful stuff,
and then this:
7/. One annual trip of 2000 miles by plane (at about 70mpg per
passenger)is peanuts compared with the 12,000 miles you do to commute
to your job at 45mpgh, or less in congestion..

OK, so for a family of four you have to multiply that up, (which you
don't for an equivalent car journey), and 2000 miles is the round-trip
so you "only" get to go 1000 miles away.

To be more realistic, a single holiday to (say) New York for a family of
four equates to an approx. total round trip of 8000 miles per passenger,
so 32,000 miles at 70mpg. So that's the equivalent fuel use of 16,000
miles in a 35mpg car, which is substantially more than I do in a year.

Simon.

I wonder how much of what you consume is airfreighted in, though.

If fuel costs go high enough, time to unmothball the 'queen mary' or
whatever..

whats a liner do..40mph? 3000 miles..? 75 hours..thats three and a bit days.

Nice trip.

In message , at 12:10:21 on
Mon, 22 Jan 2007, The Natural Philosopher remarked:
whats a liner do..40mph? 3000 miles..? 75 hours..thats three and a bit days.

The problem is that for many USA destinations there's another thousand
or two miles to go ! And they don't have many trains left running.
--
Roland Perry

Roland Perry wrote:
In message , at 12:10:21 on
Mon, 22 Jan 2007, The Natural Philosopher remarked:
whats a liner do..40mph? 3000 miles..? 75 hours..thats three and a bit
days.

The problem is that for many USA destinations there's another thousand
or two miles to go ! And they don't have many trains left running.

The reality is that international travel and commerce exists the way it
does because of the cheap cost of fuel.

If that gets expensive. travel patterns will alter to suit.

If a return ticket to LA was 6000 quid not 600, a lot of people would
decide that they really didn't need to go there all that often.

The Natural Philosopher wrote:
Roland Perry wrote:
In message , at 12:10:21 on
Mon, 22 Jan 2007, The Natural Philosopher remarked:
whats a liner do..40mph? 3000 miles..? 75 hours..thats three and a
bit days.

The problem is that for many USA destinations there's another thousand
or two miles to go ! And they don't have many trains left running.

The reality is that international travel and commerce exists the way it
does because of the cheap cost of fuel.

If that gets expensive. travel patterns will alter to suit.

If a return ticket to LA was 6000 quid not 600, a lot of people would
decide that they really didn't need to go there all that often.

...oh and of course nuclear electric generation and 400mph trains are
ideal for the USA.

With loading times being far faster, coast to coast times would be
similar to a subsonic airliner.

Need to lay some decent track mind you..

On Mon, 22 Jan 2007 12:39:27 +0000 The Natural Philosopher wrote :
The reality is that international travel and commerce exists the
way it does because of the cheap cost of fuel.

If that gets expensive. travel patterns will alter to suit.

http://business.guardian.co.uk/story/0,,1837748,00.html gives BA's
summer quarter figures, £2.3bn sales, £512m of which went on fuel.
So, simplistically I admit, fuel prices can double and only put 22%
on fares.

If a return ticket to LA was 6000 quid not 600, a lot of people
would decide that they really didn't need to go there all that
often.

If fuel prices went up that much, they wouldn't be able to afford
the cab to the airport!

--
Tony Bryer SDA UK 'Software to build on' http://www.sda.co.uk

Tony Bryer wrote:
On Mon, 22 Jan 2007 12:39:27 +0000 The Natural Philosopher wrote :
The reality is that international travel and commerce exists the
way it does because of the cheap cost of fuel.

If that gets expensive. travel patterns will alter to suit.

http://business.guardian.co.uk/story/0,,1837748,00.html gives BA's
summer quarter figures, £2.3bn sales, £512m of which went on fuel.
So, simplistically I admit, fuel prices can double and only put 22%
on fares.

If a return ticket to LA was 6000 quid not 600, a lot of people
would decide that they really didn't need to go there all that
often.

If fuel prices went up that much, they wouldn't be able to afford
the cab to the airport!

unless it was nuclear electric..

There is a lot to be said for raising fuel prices until the alternatives
ARE cost competitive...