I have been planning to fit an oil boiler in my house, however I am not
all that happy about the running costs. I have considered a heat pump,
but I am not sure that the up-front outlay is worth the extra economy.

What I am very confused about is how much it would cost to run a heat
pump - googling this group gives two conflicting opinions:

1) Oil is now so expensive that it costs about the same to run as
electricity for CH + DHW.

2) Although a heat pump runs between 300% and 400% efficiency they use
"expensive" electricity and so when you compare overall running costs
it would be just as cheap to run oil.

How can both of these be true?

If my house requires 40,000kWh per year (rough stab) for CH + DHW and I
get this all by off-peak electricity at 3.07p + VAT per kWh (ZEST4
online) it would cost £1289.40 per year to run.

If I get the same amount of heat from a heat pump, and pay 7.23p + VAT
per kWh (Scottish Hydro standard rate) the break-even point for
efficiency is when the system uses 16,985kWh of electricity which is
235% efficiency. If I could manage an avaerage of 300% efficiency I
would save about £277 per year.

Assuming an oil system at 33p per litre and about 10.5kWh per litre and
an 80% efficient system... this gives £1587 for 40,000kWh! (Yikes)

So, I guess the big question is how much would it cost to install a
heat pump system? If it costs less than about £3000 more than an oil
system it looks like it would pay for itself in 5 years.

In article .com,
Matt Beard wrote:
So, I guess the big question is how much would it cost to install a
heat pump system? If it costs less than about £3000 more than an oil
system it looks like it would pay for itself in 5 years.

The oil-fired system has the extra overhead of servicing, also the
possible inconvenience of dealing with oil deliveries. I don't know
what's involved with heat pump systems but my last fridge was still
working after 23 years.

--
Tony Bryer SDA UK 'Software to build on' http://www.sda.co.uk
Free SEDBUK boiler database browser http://www.sda.co.uk/qsedbuk.htm
[Latest version QSEDBUK 1.10 released 4 April 2005]

Tony Bryer wrote:
In article .com,
Matt Beard wrote:
So, I guess the big question is how much would it cost to install a
heat pump system? If it costs less than about £3000 more than an oil
system it looks like it would pay for itself in 5 years.

The oil-fired system has the extra overhead of servicing, also the
possible inconvenience of dealing with oil deliveries. I don't know
what's involved with heat pump systems but my last fridge was still
working after 23 years.

--
Tony Bryer SDA UK 'Software to build on' http://www.sda.co.uk
Free SEDBUK boiler database browser http://www.sda.co.uk/qsedbuk.htm
[Latest version QSEDBUK 1.10 released 4 April 2005]

Would it be possible to run your boiler on cooking oil, or has that one
been covered. Not sure on the price of heating oil / with cooking oil.


Regards

Darren

In article .com,
Darren_forward wrote:
Would it be possible to run your boiler on cooking oil, or has that one
been covered. Not sure on the price of heating oil / with cooking oil.

The way BBC2 Working Lunch has been talking up waste cooking oil it will
soon be more expensive than the real thing g. Chip shop owners used to
have to pay to get it taken away; now they get paid for it.

--
Tony Bryer SDA UK 'Software to build on' http://www.sda.co.uk
Free SEDBUK boiler database browser http://www.sda.co.uk/qsedbuk.htm
[Latest version QSEDBUK 1.10 released 4 April 2005]

Hi Matt,

Answering your first question, I think the second opinion is out of
date. The first one is true if you use off peak electricity but not on
peak.

Next, you can do much better than 80% efficiency - try 95% and that
means an oil cost of £1323.

Also, I'm not sure how large or energy efficient your house is, but 40K
kWh per year seems steep. I am only using 26K. I would get an accurate
figure rather than a rough stab as this greatly affects the payback
time.

That said, if I were doing my renovation again, I would probably go the
heat pump route because oil looks like it will keep increasing in price
faster than electricity.

Costs for a heat pump are hard to work out but £3000.00 more than an
oil boiler after grants is probably about right but the installation
work is more expensive for a heat pump which would increase this
difference. Unfortunately, I never worked out the cost of this as I
would do all the work apart from the commissioning myself.

I'm not sure if you are building a new place or adding this to an old
place but another factor to consider is that using under floor heating
is more efficient for heat pumps because they don't have to heat the
water up to very high temperatures. I've never been able to find out
accurate figures for the differences in efficiency though...

Finally, I have thought about running a heat pump from off-peak
electricity and storing the output in a thermal store to use during the
day. I guess this might require a larger pump and collector and there
will be inefficiencies in the thermal store but my gut feeling is that
it would save money and the thermal store could be combined with solar
thermal during the summer.

Cheers,

Alan.

Alan wrote:
Next, you can do much better than 80% efficiency - try 95% and that
means an oil cost of £1323.

I'm assuming "real-world" figures - the 95% sedbuk figure is only
achieved when running at certain flow rates with certain temperature
differential (I don't know how fast it falls away though) and after 5
or 10 years I doubt that it will still run at 95% at any point.


Also, I'm not sure how large or energy efficient your house is, but 40K
kWh per year seems steep. I am only using 26K. I would get an accurate
figure rather than a rough stab as this greatly affects the payback
time.

The house is a detached granite building with not much insulation (and
little scope for improving it short of totally stripping out and
rebuilding) and it is in the north of Scotland. It takes a lot of
heating! Last year I spent just short of £2000 on electric heating and
it still felt cold.

I'm not sure if you are building a new place or adding this to an old
place but another factor to consider is that using under floor heating
is more efficient for heat pumps because they don't have to heat the
water up to very high temperatures. I've never been able to find out
accurate figures for the differences in efficiency though...

I hate solid floors - if I can't have a carpet under-foot I'm not
comfortable! I have rented houses with laminate and have relatives
with solid wood and even stone floors - I just can't wait to get back
home! So underfloor is not that good an idea (especially with suspended
wooden floors) so it's likely to be radiators.

darren_forward wrote:
Would it be possible to run your boiler on cooking oil, or has that one
been covered. Not sure on the price of heating oil / with cooking oil.


Regards

Darren

Isn't that illegal?

Hi,

You are probably right that after a few years, the new efficiencies
will be hard to meet. I wonder if this is true of heat pumps?

If you know you spent £2000 on electric heating then you can work out
exactly how many KW you used to heat the house although I agree that
40K kWh is probably not far off. I live in a granite house myself and I
know that they are cool in summer and freezing in winter. I am glad
that I have at least some insulation. I feel for you!.

You can have UFH with suspended floors but unfortunately this isn't
much use unless you are building new or completely redoing a place.

Please let us know what you eventually decide on and also what it costs
you. I for one am very interested to hear how you get on.

All the best,

Alan.

"Tony Bryer" wrote in message
...
In article .com,
Matt Beard wrote:
So, I guess the big question is how much would it cost to install a
heat pump system? If it costs less than about £3000 more than an oil
system it looks like it would pay for itself in 5 years.

The oil-fired system has the extra overhead of servicing, also the
possible inconvenience of dealing with oil deliveries. I don't know
what's involved with heat pump systems but my last fridge was still
working after 23 years.

The best thing is to install cavity wall insulation, insulation around the
slab perimiter underground (assuming a concrete slab) and over 1 foot in the
loft. Triple glazed windows with low E glass and make the place as air tigt
as possible too. Do a heat loss calc on that spec. You may find that a
cheap oil boiler or even LPG will be more cost effcetive as you will use
less energy.

For very cheap heat pumps, solar panel, and the rest:
http://www.navitron.org.uk/

"Alan" wrote in message
oups.com...


Hi Matt,

Answering your first question, I think the second opinion is out of
date. The first one is true if you use off peak electricity but not on
peak.

Next, you can do much better than 80% efficiency - try 95% and that
means an oil cost of £1323.

Also, I'm not sure how large or energy efficient your house is, but 40K
kWh per year seems steep. I am only using 26K. I would get an accurate
figure rather than a rough stab as this greatly affects the payback
time.

That said, if I were doing my renovation again, I would probably go the
heat pump route because oil looks like it will keep increasing in price
faster than electricity.


The two are linked.


Finally, I have thought about running a heat pump from off-peak
electricity and storing the output in a thermal store to use during the
day. I guess this might require a larger pump and collector and there
will be inefficiencies in the thermal store but my gut feeling is that
it would save money and the thermal store could be combined with solar
thermal during the summer.


Good approach.

"Matt Beard" wrote in message
ups.com...

Alan wrote:
Next, you can do much better than 80% efficiency - try 95% and that
means an oil cost of £1323.

I'm assuming "real-world" figures - the 95% sedbuk figure is only
achieved when running at certain flow rates with certain temperature
differential (I don't know how fast it falls away though) and after 5
or 10 years I doubt that it will still run at 95% at any point.

Do a google on me on heat pumps.

"Matt Beard" wrote in message
ups.com...


So underfloor is not that good an idea (especially with suspended
wooden floors) so it's likely to be radiators.

A heat pump is a waste of time then.

"Matt Beard" wrote in message
oups.com...
darren_forward wrote:
Would it be possible to run your boiler on cooking oil, or has that one
been covered. Not sure on the price of heating oil / with cooking oil.


Regards

Darren

Isn't that illegal?

No. Not paying tax on it is.

"Alan" wrote in message
oups.com...

You can have UFH with suspended
floors but unfortunately this isn't
much use unless you are building new or completely redoing a place.

Best he insulates under the floors.

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember "Doctor Drivel"
saying something like:


"Matt Beard" wrote in message
roups.com...
darren_forward wrote:
Would it be possible to run your boiler on cooking oil, or has that one
been covered. Not sure on the price of heating oil / with cooking oil.


Regards

Darren

Isn't that illegal?

No. Not paying tax on it is.

You can burn it as a heating fuel free as a bird.
--

Dave

"Grimly Curmudgeon" wrote in message
...
We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember "Doctor Drivel"
saying something like:


"Matt Beard" wrote in message
roups.com...
darren_forward wrote:
Would it be possible to run your boiler on cooking oil, or has that
one
been covered. Not sure on the price of heating oil / with cooking
oil.


Regards

Darren

Isn't that illegal?

No. Not paying tax on it is.

You can burn it as a heating fuel free as a bird.

No problem then, but put it in your car and the C&E man will have you.

On 8 Nov 2005 08:28:46 -0800, Matt Beard wrote:

Alan wrote:
Next, you can do much better than 80% efficiency - try 95% and that
means an oil cost of £1323.

I'm assuming "real-world" figures - the 95% sedbuk figure is only
achieved when running at certain flow rates with certain temperature
differential (I don't know how fast it falls away though) and after 5
or 10 years I doubt that it will still run at 95% at any point.


Also, I'm not sure how large or energy efficient your house is, but 40K
kWh per year seems steep. I am only using 26K. I would get an accurate
figure rather than a rough stab as this greatly affects the payback
time.

The house is a detached granite building with not much insulation (and
little scope for improving it short of totally stripping out and
rebuilding) and it is in the north of Scotland. It takes a lot of
heating! Last year I spent just short of £2000 on electric heating and
it still felt cold.

I'm not sure if you are building a new place or adding this to an old
place but another factor to consider is that using under floor heating
is more efficient for heat pumps because they don't have to heat the
water up to very high temperatures. I've never been able to find out
accurate figures for the differences in efficiency though...

I hate solid floors - if I can't have a carpet under-foot I'm not
comfortable! I have rented houses with laminate and have relatives
with solid wood and even stone floors - I just can't wait to get back
home! So underfloor is not that good an idea (especially with suspended
wooden floors) so it's likely to be radiators.

Mmm.

Couple of thoughts

(i) Electriciy generation apart from nuclear (25%) and non fossil (about
5%) is mainly tied to raw fossil fuel prices. We do use coal a bit but the
bulk of electricity generation is gas., Gas is going up JUST as fast as
oil..so you may excpect electricity to actally go up anyway.

(ii) Burning oil at 60% efficiency to make electrcity that is transported
at 95% efficiency is not as efficient as burning oil in the home at 70%
efficiency.

(iii) insulation is what you need. Dry line that granite pile mate!

(iv) U/F heating will work with carpets. ...BUT what is critical is the
thermal resistance between the heat source and the room and the heat source
and the cold ground underneath., With a ventilated raised wooden floor
though, you are in trouble: You need massive underfloor insulation to
ensure the bulk of the heat transfer is upwards, and a higher in-floor
temperature to heat the room through the carpet. This may exceed sensible
limits with a wooden floor and lead to high levels of wood movement.