We live in a rural location and inherited a central heating system
which runs on propane delivered by Shell to a large tank in the
garden.

I'm considering the alternatives and, as part of this exercise, have
calculated what I think the propane costs per kwH.

It's about 35p/litre at the moment and the calorific value I have
found is about 7kwH per litre. So this gives a cost of something
around 5p per kwH.

Presumably however this is before boiler efficiency is taken into
account so, given that it's an old boiler (a Potterton NetaHeat) I
guess that is somewhere around 50% - or is it even worse than that?

So my hot water and heating by gas is costing something like 10p per
kwH or even more - eek. We'll use the overnight electricity at around
3p/kwH even more then!

--
Chris Green

wrote in message
...
We live in a rural location and inherited a central heating system
which runs on propane delivered by Shell to a large tank in the
garden.

I'm considering the alternatives and, as part of this exercise, have
calculated what I think the propane costs per kwH.

It's about 35p/litre at the moment and the calorific value I have
found is about 7kwH per litre. So this gives a cost of something
around 5p per kwH.

Presumably however this is before boiler efficiency is taken into
account so, given that it's an old boiler (a Potterton NetaHeat) I
guess that is somewhere around 50% - or is it even worse than that?

I would have thought that the old boiler was atleast 70% efficient.

In part it does depend how you treat the waste heat. If the boiler is say in
the kitchen, then likely part of the waste heat is keeping the kitchen warm
rather than going up the chimney.


I use 28 sec heating oil. At a nominal calorific value of 19,600 Btu/lb which I
make 10.57 kwh/L this works out at 2.83 pence/kwh at 30p /litre. My new non
condensing boiler has a claimed efficiency of 85.1% which gives a price per kwh
of 3.335 p/kwh which is just less that the 3.393 p/kwh I am now paying for off
peak electricity! Of course there are pipe wok losses.

When I last did this calculation oil was 15p/litre!


Have you considered one of those heat pump solutions that gets the heat out of
the ground?

I am not a fan of propane, even for cooking out induction hob is at least as
good, and certainly saver than gas.

My neighbour arranges the heating oil for a number of us. He just uses who ever
is the cheapest supplier at the time.

--

Michael Chare

wrote:
We live in a rural location and inherited a central heating system
which runs on propane delivered by Shell to a large tank in the
garden.

I'm considering the alternatives and, as part of this exercise, have

I'm in the middle of a 'my heating bills are too high AAARRGH'
excersize.

YHMV of course.

First, go round the entire structure, and find out the actual
composition of everything.
Now, work out the heat losses through walls, windows, floors, roof, and
any other.

Depending on how much DIY you are willing to do, you can then get on
with considering various alternatives.
Insulation varies from around 2 pounds a square meter (rockwool, 100mm)
to 12 pounds a square meter, for 100mm kingspan.

It turned out that in total, to insulate my 110m^2 of walls, I needed as
the cheapest way, several sheets of kingspan (to do round the 50cm deep
windows, and to avoid having to cut in too deeply(diamond angle grinder
+SDS)) about 10 rolls of rockwool, and about 40 sheets of plasterboard,
and 20 rolls of kitchen foil.

I could also have spent about 300 quid on wood to put this together, but
am reclaiming most from the wood ripped out - it would be faster to do
it the other way.

The total will come in substantially under a grand, and will pay back in
3 winters (including this one).

This takes the walls to current standards - in my case from an average
of around 3Kw heat departing from the walls, down to 400W.
Much more is diminishing returns.

Attic of course is cheapest, if uninsulated, but you're probably not
that lucky.
Consider payback times on everything, after actually calculating the
heat losses.
My first instinct would have been to replace the windows with double
glazed units, after manufacturing new window tops.
However, actual calculation revealed that the windows lose well under a
quarter of the heat. Less with curtains closed.

Michael Chare wrote:
wrote in message
...
We live in a rural location and inherited a central heating system
which runs on propane delivered by Shell to a large tank in the
garden.

I'm considering the alternatives and, as part of this exercise, have
calculated what I think the propane costs per kwH.

It's about 35p/litre at the moment and the calorific value I have
found is about 7kwH per litre. So this gives a cost of something
around 5p per kwH.

Presumably however this is before boiler efficiency is taken into
account so, given that it's an old boiler (a Potterton NetaHeat) I
guess that is somewhere around 50% - or is it even worse than that?

I would have thought that the old boiler was atleast 70% efficient.

In part it does depend how you treat the waste heat. If the boiler is say in
the kitchen, then likely part of the waste heat is keeping the kitchen warm
rather than going up the chimney.

It's a balanced flue so the only waste heat not lost is anything that
comes through the case.


I use 28 sec heating oil. At a nominal calorific value of 19,600 Btu/lb which I
make 10.57 kwh/L this works out at 2.83 pence/kwh at 30p /litre. My new non
condensing boiler has a claimed efficiency of 85.1% which gives a price per kwh
of 3.335 p/kwh which is just less that the 3.393 p/kwh I am now paying for off
peak electricity! Of course there are pipe wok losses.

When I last did this calculation oil was 15p/litre!


Have you considered one of those heat pump solutions that gets the heat out of
the ground?

We have lots of wood and already have a big wood burning stove and are
considering a second one.

I am not a fan of propane, even for cooking out induction hob is at least as
good, and certainly saver than gas.

We will continue to use it for cooking as our panware is too varied to
manage with an induction hob.

--
Chris Green

Ian Stirling wrote:
wrote:
We live in a rural location and inherited a central heating system
which runs on propane delivered by Shell to a large tank in the
garden.

I'm considering the alternatives and, as part of this exercise, have

I'm in the middle of a 'my heating bills are too high AAARRGH'
excersize.

I was more interested in seeing the relative costs of propane and
electricity. I just want to confirm my calculations which suggest
that electricity is very little different in cost from propane even at
peak rates. Thus simply not using our gas central heating, using our
wood burners more (we have lots of our own wood) and topping up with
electric heating will save us money.

I agree with your insulation approach, that's going to save money
(assuming current insulation is poor) regardless of what fuel is being
used.

--
Chris Green

wrote in message
...
We live in a rural location and inherited a central heating system
which runs on propane delivered by Shell to a large tank in the
garden.

I'm considering the alternatives and, as part of this exercise, have
calculated what I think the propane costs per kwH.

It's about 35p/litre at the moment and the calorific value I have
found is about 7kwH per litre. So this gives a cost of something
around 5p per kwH.

Presumably however this is before boiler efficiency is taken into
account so, given that it's an old boiler (a Potterton NetaHeat) I
guess that is somewhere around 50% - or is it even worse than that?

So my hot water and heating by gas is costing something like 10p per
kwH or even more - eek. We'll use the overnight electricity at around
3p/kwH even more then!

--
Chris Green

Are you paying a competitive price. I pay just under 26p/l. The average
price of lpg for road use is 39.9 p/l
http://www.whatprice.co.uk/car/local-LPG-prices.php and that includes duty
of 7.82p/l + VAT at 17.5%.
Time to switch? see the documents at
http://www.competition-commission.or...006/514lpg.htm .I
don't know if the "order" implementing the recommendations has been made but
the suppliers know what is coming.

PeterK

On Thu, 09 Nov 2006 09:47:09 +0000, tinnews wrote:

Michael Chare wrote:
wrote in message
...
We live in a rural location and inherited a central heating system
which runs on propane delivered by Shell to a large tank in the
garden.

I'm considering the alternatives and, as part of this exercise, have
calculated what I think the propane costs per kwH.

It's about 35p/litre at the moment and the calorific value I have
found is about 7kwH per litre. So this gives a cost of something
around 5p per kwH.

Presumably however this is before boiler efficiency is taken into
account so, given that it's an old boiler (a Potterton NetaHeat) I
guess that is somewhere around 50% - or is it even worse than that?

I would have thought that the old boiler was atleast 70% efficient.

In part it does depend how you treat the waste heat. If the boiler is say in
the kitchen, then likely part of the waste heat is keeping the kitchen warm
rather than going up the chimney.

It's a balanced flue so the only waste heat not lost is anything that
comes through the case.


In fact it has a fanned flue with electronic ignition so it is towards the
better end of the non-condensing spectrum. In fact for it era it was
exceptional. Probably has SEDBUK of around 75-80%



--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html
Gas Fitting Standards Docs he http://www.makewrite.demon.co.uk/GasFittingStandards

Ed Sirett wrote:
On Thu, 09 Nov 2006 09:47:09 +0000, tinnews wrote:

Michael Chare wrote:
wrote in message
...
We live in a rural location and inherited a central heating system
which runs on propane delivered by Shell to a large tank in the
garden.

I'm considering the alternatives and, as part of this exercise, have
calculated what I think the propane costs per kwH.

It's about 35p/litre at the moment and the calorific value I have
found is about 7kwH per litre. So this gives a cost of something
around 5p per kwH.

Presumably however this is before boiler efficiency is taken into
account so, given that it's an old boiler (a Potterton NetaHeat) I
guess that is somewhere around 50% - or is it even worse than that?

I would have thought that the old boiler was atleast 70% efficient.

In part it does depend how you treat the waste heat. If the boiler is say in
the kitchen, then likely part of the waste heat is keeping the kitchen warm
rather than going up the chimney.

It's a balanced flue so the only waste heat not lost is anything that
comes through the case.


In fact it has a fanned flue with electronic ignition so it is towards the
better end of the non-condensing spectrum. In fact for it era it was
exceptional. Probably has SEDBUK of around 75-80%

Yes, sorry, you're quite right. I was just trying to say that it
hasn't got a big diameter pipe coming out of the top of it.

The efficiency surprises me, I didn't realise that gas boilers of that
vintage were so good. Anyway it doesn't affect my calculations all
*that* much, it's still much cheaper to use electricity overnight to
heat our water and it's a toss-up during the day between electtricity
and gas for heating.

--
Chris Green

On Fri, 10 Nov 2006 08:59:54 +0000, tinnews wrote:

Ed Sirett wrote:
On Thu, 09 Nov 2006 09:47:09 +0000, tinnews wrote:

Michael Chare wrote:
wrote in message
...
We live in a rural location and inherited a central heating system
which runs on propane delivered by Shell to a large tank in the
garden.

I'm considering the alternatives and, as part of this exercise, have
calculated what I think the propane costs per kwH.

It's about 35p/litre at the moment and the calorific value I have
found is about 7kwH per litre. So this gives a cost of something
around 5p per kwH.

Presumably however this is before boiler efficiency is taken into
account so, given that it's an old boiler (a Potterton NetaHeat) I
guess that is somewhere around 50% - or is it even worse than that?

I would have thought that the old boiler was atleast 70% efficient.

In part it does depend how you treat the waste heat. If the boiler is say in
the kitchen, then likely part of the waste heat is keeping the kitchen warm
rather than going up the chimney.

It's a balanced flue so the only waste heat not lost is anything that
comes through the case.


In fact it has a fanned flue with electronic ignition so it is towards the
better end of the non-condensing spectrum. In fact for it era it was
exceptional. Probably has SEDBUK of around 75-80%

Yes, sorry, you're quite right. I was just trying to say that it
hasn't got a big diameter pipe coming out of the top of it.

The efficiency surprises me, I didn't realise that gas boilers of that
vintage were so good.

They generally weren't but that model was. Although it's flue pipe and
terminal are unique they were much smaller than the massive flues and
terminals of their contemporaries.

--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html
Gas Fitting Standards Docs he http://www.makewrite.demon.co.uk/GasFittingStandards