Calculating fuel oil consumption

CharlieAlpha_2

I know how to calculate the cost or running an electrical item, such as a radiant panel electric heater - but does anyone know how to calculate the cost of running an oil fired CH/HW boiler such as a Boulter Camray 5 please..?

For illustration purposes, let's assume its output is 20kW.

Thanks in advance to anyone who can assist me here.

owned_by_2_Siamese

hi - here's a way to work out how much your boiler costs per kilowatt (so you can compare it to electric where the price is allways given it kilowats. I make no promises about its accuracy/validity! It will only tell you the cost of your boilers output -

You can get your boilers efficincy by searching for SEDBUK on the net. If its not condensing and its more than three years old - I'd 'guess' at 70%

Hope it helps!


Originally Posted by owned by 2 Siamese
Spent a long time wrestling with this before I actually bought a house with oil. This is how I worked it out (hopefully its reasonably logical!)

Working out the cost of a KW of heat from oil (so you can compare to electric/gas)

- a litre of heating oil (kerosene 28 sec) burnt at 100% efficiency will release approximately 10KW of heat (this was a consistent figure from various internet/oil websites I searched in March)
- You now need to know the SEDBUK efficiency of your boiler (always given as a %) (if you're buying a new condensing biler the manufacturers website should tell you this)
- mutiply 10KW by the SEDBUK Efficiency (this is how much you'll get as useable heat from your boiler)

I have a condensing Worcester Danesmore boiler - (1 year old) quoting 92% so for every litre of oil I get 9.2KW of useable heat (if your boiler is more efficient you get more - and vice versa)

So a litre of oil (currently an eye watering 38.9p, plus VAT at 5% = 40.8p
take this figure and divide by the useable heat (9.2 for me) = 40.8/9.2 = 4.4p

This means that in effect each KW cost me 4.4p - and I can compare that to electricty (I'm paying about 8.5p inc VAT) so all told, comapred to standard daytime its cheaper to use oil - if you know your offpeak tarrif then you can compare (but remember to add on any increased day tariff if necessary).

When I looked LPG had a lower KWH per litre - but can find my notes to say how much - all I know was it worked out a lot more expensive.

Not sure if this proves anything other than how sad I am - or if it would ever pass any kind of 'review' but its the best I could find!

Cardew

You can't use a figure of 20kW as any form of comparison.

That is like me saying my Ferrari(I wish!) can produce 430 BHP. It can produce that power, but on the motorway it is probably only using 50bhp at a steady 70MPH.

The post above is spot on with how to work out oil costs; generally expect to pay between 4p and 6p/kWh. Thus always cheaper than(non storage) electrical heating and always more than gas.

wotadog

I have just done the calculation with my last lot of oil costing 61.3ppl inc vat. It still works out slightly cheaper for the oil, but it looks like it is gaining on the electric rapidly.

bobmedley

http://www.homeheatingguide.co.uk/efficiency-tables.php?make=Boulter

Here is a link to your boiler efficiency, so you need to pick your exact model

Calculation is;

oil = 10.27 kw hr per litre
Your boiler is 'x'% efficient

If todays price is 55p, then the 'x'% efficiency gives you 10.27 x 'x'% = kw per litre. Divide cost by result equals cost per kw for your boiler.

Example for Camray 5 65/95

84.6% efficient, so each litre gives 10.27 x 84.6% = 8.69 kw per litre

55p per litre divided by 8.69 kw = 6.33p per kw

So the cost for this particular boiler at todays oil price is 6.33p per kw