We've just had our first gas bill (for heating and cooking) since the cavity
wall insulation was installed mid-December.

Last winter (Nov 07- Mar 08) - average daily usage 10 units per day
This winter (Dec 08 - Mar 09) - average daily usage 7 units per day !

I didn't expect it would make that much difference, and I'd say that this
has probably been a colder winter than last year.

I reckon that means we should pay back the (70% subsidised) cost in about 15
months.

On Mar 9, 3:42*pm, "OG" wrote:
We've just had our first gas bill (for heating and cooking) since the cavity
wall insulation was installed mid-December.

Last winter (Nov 07- Mar 08) - average daily usage 10 units per day
This winter (Dec 08 - Mar 09) - average daily usage 7 units per day !

I didn't expect it would make that much difference, and I'd say that this
has probably been a colder winter than last year.

I reckon that means we should pay back the (70% subsidised) cost in about 15
months.

How did temperature days units compare, a bill is meaningless without
knowing temp heating days. So i say it was warmer this year.

ransley wrote:
On Mar 9, 3:42 pm, "OG" wrote:
We've just had our first gas bill (for heating and cooking) since the cavity
wall insulation was installed mid-December.

Last winter (Nov 07- Mar 08) - average daily usage 10 units per day
This winter (Dec 08 - Mar 09) - average daily usage 7 units per day !

I didn't expect it would make that much difference, and I'd say that this
has probably been a colder winter than last year.

I reckon that means we should pay back the (70% subsidised) cost in about 15
months.

How did temperature days units compare, a bill is meaningless without
knowing temp heating days. So i say it was warmer this year.

Oh good, if you've got (Dec, Jan, Feb) temperature stats for (07-08) and
(08-09) for Liverpool I'd be really interested to see them.

OG wrote:
ransley wrote:
On Mar 9, 3:42 pm, "OG" wrote:
We've just had our first gas bill (for heating and cooking) since the
cavity
wall insulation was installed mid-December.

Last winter (Nov 07- Mar 08) - average daily usage 10 units per day
This winter (Dec 08 - Mar 09) - average daily usage 7 units per day !

I didn't expect it would make that much difference, and I'd say that
this
has probably been a colder winter than last year.

I reckon that means we should pay back the (70% subsidised) cost in
about 15
months.

How did temperature days units compare, a bill is meaningless without
knowing temp heating days. So i say it was warmer this year.

Oh good, if you've got (Dec, Jan, Feb) temperature stats for (07-08) and
(08-09) for Liverpool I'd be really interested to see them.

Thanks for the head up - I've not come across temp heating days before,
but I found a definition on Wikipedia and the monthly stats for
Liverpool on Weather Underground

Weather Heating days (monthly Sums base 65)
Dec 07: 661, Dec 08: 744
Jan 08: 622, Jan 09: 805
Feb 08: 649, Feb 08: 676

Average Mean daily Temperatures
Dec 07: 5C, Dec 08: 4C
Jan 08: 7C, Jan 09: 3C
Feb 08: 5C, Feb 08: 4C

So it looks to this novice like it /has/ been colder this year.

OG wrote:
We've just had our first gas bill (for heating and cooking) since the
cavity wall insulation was installed mid-December.

Last winter (Nov 07- Mar 08) - average daily usage 10 units per day
This winter (Dec 08 - Mar 09) - average daily usage 7 units per day !

I didn't expect it would make that much difference, and I'd say that
this has probably been a colder winter than last year.

I reckon that means we should pay back the (70% subsidised) cost in
about 15 months.


I can't give any figures of my own because I've had cavity insulation
for a long time in various houses. However I think the saving might well
be better than the raw heat leakage figures. Our sensation of warmth is
determined by the temeperature of the walls not the air in the room.
ISTR that this is called Prevost's Theory of Exchanges or somesuch.
Objects in a container exchange radiated heat with the walls not the
air. When you insulate, the temperature of the walls goes up and very
likely you can have a lower room air temperature and still feel warm.
It's also why when you get home from holiday it takes a while before you
feel warm even after the air is warmed. Or is it just that you've been
baking on the beach?

Anyway it's great to be saving money and energy. Just put another 10cm
in the loft and you'll be turning the heating off altogether!

Peter Scott

"OG" wrote in message
...
OG wrote:
ransley wrote:
On Mar 9, 3:42 pm, "OG" wrote:
We've just had our first gas bill (for heating and cooking) since the
cavity
wall insulation was installed mid-December.

Last winter (Nov 07- Mar 08) - average daily usage 10 units per day
This winter (Dec 08 - Mar 09) - average daily usage 7 units per day !

I didn't expect it would make that much difference, and I'd say that
this
has probably been a colder winter than last year.

I reckon that means we should pay back the (70% subsidised) cost in
about 15
months.

How did temperature days units compare, a bill is meaningless without
knowing temp heating days. So i say it was warmer this year.

Oh good, if you've got (Dec, Jan, Feb) temperature stats for (07-08) and
(08-09) for Liverpool I'd be really interested to see them.

Thanks for the head up - I've not come across temp heating days before,
but I found a definition on Wikipedia and the monthly stats for Liverpool
on Weather Underground

Weather Heating days (monthly Sums base 65)
Dec 07: 661, Dec 08: 744
Jan 08: 622, Jan 09: 805
Feb 08: 649, Feb 08: 676

Average Mean daily Temperatures
Dec 07: 5C, Dec 08: 4C
Jan 08: 7C, Jan 09: 3C
Feb 08: 5C, Feb 08: 4C

So it looks to this novice like it /has/ been colder this year.

Coldest winter for 13 years.

http://news.bbc.co.uk/1/hi/uk/7921230.stm

My cavity wall insulation has paid for itself in less than12 months. My
quick payback time is due to the low price I paid for the installation, the
way my house is constructed (not normal bricks), having a gable end that is
exposed to the Pennines and the price increases of gas.

Cavity wall insulation usually take 2 to 4 years payback time.

Adam

On Tue, 10 Mar 2009 08:33:53 +0000 someone who may be Peter Scott
wrote this:-

Our sensation of warmth is
determined by the temeperature of the walls not the air in the room.

Not quite. How warm people feel depends on a number of factors which
do include radiation from objects (including walls) but also include
air temperature, air velocity, the occupants themselves and what
they are doing.

When you insulate, the temperature of the walls goes up and very
likely you can have a lower room air temperature and still feel warm.

That is indeed a factor in lower air temperatures being possible
without affecting comfort..


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

OG wrote:

I reckon that means we should pay back the (70% subsidised) cost in about
15 months.

Possibly a bit longer, hopefully we might manage to get some warm weather in
the summer when the heating won't be needed anyway. So it might take 15
winter type months for payback, but still a good return.

--
Mike Clarke