switching from oil to lpg

dave-m53

my current heating system is oil and im thinking of switching to lpg do you think this is a good idea as oil is 61p a litre and lpg is around 30- 36. anyone on lpg could give me some comparisons ie is 500 litres of gas the same or better/worse than 500 litres of oil. ive got a three bedroom semi which is the best boiler to go for ? thanks ---dave

bobmedley

The energy density of oil is higher than LPG by c44%, therefore you need to increment the LPG cost to reflect this (500 litres of gas is not equivalent to 500 litres of oil - you will need approx 890 litres of gas).

Prices obviously fluctuate, but currently there is little difference between the two when you increment the LPG cost.

LPG companies also tie you in as they own the tank & only they can fill it -I don't use LPG, but other people on these forums feel this leads to sharp practice.

The EU might be looking at this as anti-competitive - do a search of the forums, there are a lot of topics on LPG and it's suppliers.

So to summarise, from frying pan to fire.

paceinternet

Are oil and lpg boilers of comparable efficiency?

Just found this to back up bobmedley. In fact it may be 47%.
http://www.ior.com.au/ecflist.html
Fuel Energy Density
NB: Actual calorific values vary depending on fuel composition.
LPG Propane 25.3 MJ/litre
Heating Oil 37.3 MJ/litre

bobmedley

Go to;

http://www.sedbuk.com/cgi-local/dynamicv.cgi?page=boiler8)

This shows relative boiler efficiencies - the very best oil boiler is 97% and the very best LPG boiler is 93.3% efficient.

This would skew the costs even more against LPG.

paceinternet

bobmedley, using the info here from the other thread which was really about comparing 47 kg bottle prices.

If oil/lpg boilers can be of "similar" efficiency, (but for significantly different capital costs):
lpg 47kg bottle for £40.57 = 93.3 litres x 7.1kw = 662.4 kw
oil £0.60 per litre. £40.57 gets you 67.6 litres x 10.2 kw = 689 kw.
oil £0.62 per litre ....................................................................667 kw

So very close. Obviously prices can change, but this is a big surprise to me. Are we in a period where oil has increased significantly faster than lpg?
You have no fixed/annual costs with bottled lpg compared with bulk, and until the new competition commission rules become active, you can try to source bottles from the lowest cost supplier.

bobmedley

I put my calculations in the other thread about bottled gas - at your cost of £40 for a 47kg tank, then the cost is indeed around 6p per kilowatt and roughly the same as oil.

However, the original question was whether to swap from oil, so if you factor in a new boiler, tank from the supplier & bulk LPG costs that *appear* to be higher than what you can source, then it doesn't look as if it would save any money at all despite a potentially large capital investment.

Of course, it works the other way & it would appear pointless to swap from LPG to oil for the same reasons.

In fact, I am coming to the conclusion that unless you have mains gas then it is a pretty futile exercise to swap between oil/LPG/biomass/solar etc, etc as the cost of entry far outweighs any savings you can make - just my opinion:cool: