How long will a gas bottle last, how long does a BBQ sauce last and so on...

All outdoor gas appliances are rated by their energy consumption.

The cylinder capacity and energy content of the gas bottle are what determines how long it will last.

The number of hours a gas bottle lasts can be calculated by dividing the hourly consumption of your gas appliance into the available energy content of the bottle.

A traditional sized gas BBQ has 4 or 6 burners and the range is from 12MJ to 19MJ each.

Some of the new portable BBQs have only one burner and the range is from 7.5MJ to 11MJ.

To make it more challenging, some BBQ manufacturers rate their burners in BTU.

If you divide the burner rating by 948, you can get an equivalent number of Megajoules.

To determine how long the gas bottle will last, you just divide 417 by the MJ rating of the BBQ or patio heater.

You should be able to find the rating of the burners in the owner's manual.

How long does a gas bottle last depends on the number of MJ in the bottle.

The answers for how long a gas bottle lasts are just examples.

The heat output of the appliance is not indicated by the megajoules per hour ratings.

The heat output must also take into account the energy efficiency ratings of the models being compared.

Gas heater output is measured in kilowatt hour.1kWh of output is equal to 3.6 MJ of input.

Star Ratings allow us to compare the efficiency of different models of appliances.