On Tue, 29 Mar 2005 18:50:27 +0100, "Doctor Evil"
wrote:
"Andy Hall" wrote in message
.. .
On Tue, 29 Mar 2005 17:24:15 +0100, "Doctor Evil"
wrote:
For one thing
the ceilings are very high in comparison
to many properties so loss
through them is greater in proportion.
..in proportion to what?
Obviously in proportion to the losses
from houses with lower ceilings
and walls...........
What tripe. Lord hall is saying that the heat loss is less because the
ceiling is higher. Shishhhhh
Once again you demonstrate your misunderstanding of simple concepts of
physics.
If a ceiling is higher, then the wall area is greater.
If the wall area is greater, then the heat loss is greater.
If the heat loss is greater, then more energy is needed to heat the
room.
If more energy is needed to heat the room, then more money has to come
out of your piggy bank to pay for it and there is less to spend on
sweets.
Is that clearer for you now?
This doesn't alter the amount going
out through the front and back walls
which is likely to be an order of magnitude
greater than that through the roof even
if you were to only put 100mm
of insulation there.
Because more is going out through
the outside wall the roof should be neglected
then. What logic.
I didn't say that at all but simply
highlighted looking at things in
proportion.
Your proportion means that higher ceilings have less heat loss than lower
ceilings. Another Lord Hallism.
It really isn't worth bothering to answer that. I am sure that
everybody else understood.
Mad about what? Insulating the loft to
12" is hardly going mad. The house
will be reasonably air-tight as two sides
are not outsides walls.
Going over the top with one aspect
while doing nothing about the rest.
This is what the OP has said that he
will do for cost reasons.
The bedrooms when taken into isolation will greatly benefit, as the ceiling
is a large cold surface.area.
As you know, or perhaps you don't, heat losses through surfaces are
calculated using U values, surface area and temperature difference.
Multiplication is involved in this.
If it causes you difficulty, then you can buy a device calld a
calculator to work it all out.
These days they even work from the sun.
In order to calculate heat losses and costs you have to look at all
the rooms and their expected temperatures, not take them in isolation.
When replacing windows and doors
obviously install sealed units to make the house
more air-tight.
Obvious to who?
Obvious to anyone who knows anything about housing.
That's what I thought.
Not everybody want to replace
the character sash windows
with plastic hermetically sealed ones.
Sealed character windows are available.
Window replacement wasn't on the agenda anyway
It is now.
It may be on your agenda. It wasn't for this thread.
The walls will not be cavity, so
pretty well air tight
there too.
The losses through solid brick walls
in comparison even with
uninsulated cavity are huge.
Another Lord Hallism. Solid brick walls are notede for their airtightness.
Cavity walls are noted for their air leakiness.
This is one of your best for a long time.
We are talking about heat loss *through* surfaces.
A solid brick wall of two courses (228mm) has a U value of 2 W/m^2.K
A cavity wall of brick/cavity/block/plaster with no insulation has a U
value of 0.75
THese are from official tables produced by the Building Research
Establishment and represent a difference of 2.7:1 in heat loss.
Have you ever looked at a table of U
values? Do you know what they mean?
The point was air tightness. Air leakages play a large part in heat losses.
Make a poor U value house air tight and the bills drop and comfort goes up.
Put insulation in and the benefits even greater.
The discussion was not about air tightness. It makes some difference
but not as much as you imagine when ventilation is at the recommended
rate.
Not everybody wants to live
in a sealed box as you seem to advocate.
Another Lord Hall assumption. As the Canadians say "Built Tight, Ventilate
Right"
We aren't in Canada and are not talking about anything close to their
form of house construction. Making these comparisons is ridiculous.
Then the 12" of insulation will
have a great effect.
IN comparison to the heat loss
through the walls, the difference
between 150 and 300mm of loft
insulation is negligible.
Nonsense, it will have great effect in those bedrooms.
Do I need to do the sums
again to remind you?
Yeh, get the skule physics book out. The coloured bumper edition from under
your pillow.
I think we need to find your Janet and John Book of Sums....
So, in time new sealed windows would
be installed. Having the sealed loft
ceiling and 12" of insulation would
compliment that and already be in place.
Who said anything about even wanting to
replace windows?
They will be replaced. Fact.
Not within the scope of the current project.
--
..andy
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