BBQs come in various fuel options; liquid petroleum gas (LPG), natural gas, coal, wood … The most common fuel is gas, in either form, but it’s important to understand the difference between them as it affects your BBQ.
What are they?
LPG – liquified petroleum gas is a flammable mixture of hydrocarbon gases that is stored as a liquid under pressure, making it portable and efficient for use as a fuel. It’s typically pure propane and when you turn your appliance on, it turns the liquid into gas and burns.
Natural Gas – a combustible mixture of hydrocarbon gases. It consists mainly of methane (CH4), with varying levels of heavier hydrocarbons and other gases such as carbon dioxide. It’s supplied through your ‘gas mains’ or pipeline from the street to your house. NG is always a gas (never in liquid form) and is connected directly to your appliances, stove top, hot water, BBQ etc.
How are they used?
LPG – commonly used in BBQs, you’ll often see them referred to as ‘Swap-‘n’-Go’ bottles and they’re great for portability as you can use them anywhere. Generally, a BBQ will be hooked up with a 4kg or 9kg bottle and fitted with flexible hoses and a regulator, while households and businesses can be fitted with bottles from 45kg to 210kg and use fixed metal piping as they generally supply multiple appliances throughout the house. LPG needs to be replaced or refilled when they run out, either with a new bottle, or via a contractor who will top-up your large gas bottles.
Natural Gas – appliances are connected directly to your home’s fixed gas line using copper or steel pipe at a consistent and low pressure. All your appliances will come from the same gas line and if you need to add additional appliances – a BBQ for example – you will need a gas fitter to extend the gas pipe to the appliance. Natural Gas is a constant supply as it comes directly through your main supply from the street.
Performance
LPG – has a high energy content, is heavy and produces high heat therefore burns hotter than natural gas. Generally, this is preferred option for BBQs as it heats and sears meat quickly. The operating pressure of LPG is about 2.75kPa for BBQs.
Natural Gas – has a higher energy content that makes it more efficient than LPG, but its consistent low pressure makes it cooler to burn, meaning you won’t get as high heat. The operating pressure of NG is about 1.1-1.5kPa for BBQs.
Gas Pressure and how it affects your BBQ
The more appliances connected to one gas source, the less gas pressure you have.
For general LPG BBQs, this isn’t really a problem, as you connect your BBQ directly to one 4kg or 9kg gas bottle. One gas supply for one appliance.
For Natural Gas, this can become a little trickier. If you have several appliances connected to the gas line, that’s multiple diversions for gas flow. For the most part, this may not be an issue, unless you have multiple appliances running at the same time; for example, the stove top, hot water, heater and BBQ all going at the same time. The gas running through the line will diminish with each diversion, meaning the appliance at the end will have limited supply.
You can also experience diminished supply if your pipe is too small, or the gas line is too long. Both these affects the gas volume and pressure being supplied. Also ensuring that your gas regulator is rated for the total gas demand is important as this controls the flow and pressure required to run your appliances.
So, how does this affect your BBQ? The burners may not get sufficient gas, so you’ll get a smaller, weaker flame that’s more yellow than the blue that burns with natural gas. This can lead to the BBQs temperature not getting hot enough to sear and cook the meat adequately and can cause uneven heating, so you’ll end up with cold spots.
In short, if you’re using Natural Gas for your BBQ connection, and the flow and pressure is low, your BBQ will underperform as the gas pressure dictates the flame strength and cooking power.
Checking your natural gas supply
Call your licenced plumber or gas fitter!!
If you’re concerned you aren’t getting adequate gas supply to your BBQ, call your local licenced plumber or gas fitter. DO NOT undertake any gas works yourself.
Your gas fitter will check the gas pressure supply, inspect that the gas pipes are the right size and in working order and ensure the regulator is working. During this inspection, they may advise a dedicated natural gas line from the mains to any high-demand appliances, like your BBQ or hot water system, which may elevate gas flow issues as you’re reducing the number of diversions off one gas line.
Natural Gas or LPG?
There’s no right or wrong option; it all depends on your situation. LPG is portable and doesn’t require any additional installation while NG is permanently installed in one spot and you don’t have to worry about running out halfway through BBQing.
What you do need to understand is the difference. The different compositions mean different pressure levels and densities. And it’s this that will affect your BBQs gas connection.
Connecting your standard LPG BBQ to your Natural Gas line without checking the compatibility and converting the BBQ can cause real damage. You BBQs jets, gas hose and regulator all need to be converted to natural gas compatibility. If this is not done, not only could it result in your BBQ performing poorly, but it can also cause gas leaks, carbon monoxide poisoning, permanently damage your BBQ and it’s a fire hazard.
So, whether you choose LPG or Natural Gas for your BBQ connection, ensure you’re following the right steps to get the most out of your BBQing.
For more on how to convert your LPG BBQ to NG, click here.
