LPG is an excellent heating fuel as it burns well and very clean and pretty green, especially if the gas source is from field gas rather than a refinery.
There are also two main differences in the way that LPG (Propane and Butane - 60-40 in winter, 40-60 in summer)) and natural gas (Methane) are burnt. The first difference is in the energy content. LPG has a higher calorific value, or energy content, so less gas is required to produce the same amount of heat.
The second difference is in the oxygen to gas ratio required for proper combustion. LPG requires an oxygen to gas ratio of approximately 25 to 1. Natural gas requires a ratio of around 10 to 1. To achieve this difference, LPG is typically provided in a smaller quantity but at a higher pressure, drawing more oxygen with it into the combustion process.
Price comparisons aren't that easy as (i) the rate package of Natural Gas (ii) the storage of your LPG but if cylinders then NG isn't really an option (iii) time of year as LPG prices fluctuate strongly on chemical prices in summer - butane a component that can be taken into butylene manufacture. However one thing up front, is that LPG tends to be used where NG is not available.
Off-peak electricity ("Economy 7") costs about 7.5p per kWhbut peak can double. Natural gas piped into the house ("town gas") costs about 5p per kWh, assuming 90% boiler efficiency and this is one thing you need to check as you might be only 75 to 80 per cent efficient, giving a truer cost of nearer 6 to 7p.
Heating oil (kero mix)and LPG (liquefied petroleum gas, or "Calor Gas"), using similar boilers, currently provide heat at a rate equivalent to 6.2p and 6.5p per kWh respectively. I am using March pricing this year.......crude oil has come down so you should get cheaper prices now.
On the basis of fuel costs alone, gas, oil and LPG are cheaper than standard-rate electricity. But this does not take into account the costs of buying and installing boilers and fuel tanks, nor the annual maintenance costs, nor the fact that boilers have a finite life. The trade price for a new gas boiler is about £600, but you'll be lucky to find a gas fitter who will supply and install one for much less than £ 1,500.
Big companies such as British Gas routinely charge £3,000 or more.
Old gas boilers had few moving parts and could be expected to last for 30 or 40 years, but the new ones are packed full of electronics and might last 10 years or less. So let's budget £200 per year in boiler depreciation.
Then there's an annual servicing cost of at least £50 - and some readers are still paying £180 or more to British Gas for annual breakdown cover, even though this does not include a proper strip-down service. So if you who think that gas is the cheapest fuel should remember to factor in £250 to £400 per year as an extra "standing charge" when they do their calculations. (Add to that the annual landlord's gas safety certificate - £50 - and the Government's proposal that in future every home might also have to have an annual gas safety inspection.)
And there we are. Safety wise both are the same - if you ever smell gas - NEVER turn the electricity ON or OFF.....there's a spark across the switch on either on or off and it's this that causes the ignition point to the gas.