How Long Does a 45kg Gas Bottle Last
Liquid Petroleum Gas (LPG) can be used for a range of household appliances. The amount of gas used will depend on the type of appliances in your household, how often the appliances are used, and the number of people in your household.
A 45kg gas bottle could last more than a year if LPG is only used for cooking. If LPG is used for cooking and hot water for a family of four, a 45kg gas bottle should last for a couple of months. If using LPG for cooking, Rinnai hot water and home heating your gas cylinder should last for approximately one month.
You can extend the lifespan of your 45kg gas cylinder by avoiding long showers and turning off the heat pump or heaters when not needed. Keep two 45kg gas bottles on-site. When the first one is empty, swap over to bottle number 2 and order a replacement gas bottle from Elgas. This way, you will never run out of cooking gas, hot water, or gas heating in your home.
How long does a 45kg gas bottle last – examples
A 45kg gas bottle will last 244 days based on a 9 MJ cooktop burner used for 60 minutes per day. A 45kg gas bottle (45 kg LPG cylinder) lasts 44 days fuelling a 25 MJ Gas Fireplace used for 2 hours per day. Here are some typical examples of how long a 45kg gas bottle lasts:
- 16 L/min Hot Water used for 20 minutes per day lasts 52 days
- 16 L/min Hot Water used for 30 minutes per day lasts 35 days
- 9 MJ Cooktop Burner used for 60 minutes per day lasts 244 days
- 9 MJ Cooktop Burner used for 90 minutes per day lasts 163 days
- 15 MJ Gas Heater used for 3 hours per day lasts 49 days
- 15 MJ Gas Heater used for 4 hours per day lasts 37 days
- 25 MJ Gas Fireplace used for 2 hours per day lasts 44 days
- 25 MJ Gas Fireplace used for 3 hours
These estimates are based on a 45kg cylinder size running at the maximum setting/rate.
How long does a 45kg gas bottle Last – chart
Here are some estimates on how long a 45kg LPG gas bottle (45 kg LPG cylinder) will last:
| How Long Does a 45kg Gas Bottle Last? | |||
| Gas Heater | 2 hrs/day | 3 hrs/day | 4 hrs/day |
| • 15 MJ Heater | 73 days | 49 days | 37 days |
| • 25 MJ Heater | 44 days | 29 days | 22 days |
| Gas Hot Water | 10 min/day | 20 min/day | 30 min/day |
| • 16L/Min 124 MJ | 105 days | 52 days | 35 days |
| • 26L/Min 199 MJ | 66 days | 33 days | 22 days |
| Gas Cooktop | 30 min/day | 60 min/day | 90 min/day |
| • 9 MJ Burner | 489 days | 244 days | 163 days |
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• Durations shown assumes that you use the appliance on the maximum setting. • Gas consumption would be less, and the duration longer, on lower settings. • Numbers have been rounded and are only estimates.
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Read more to learn exactly how to calculate for your home…
A 14.2kg cooking gas bottle will last from about 9 days to 81 days, depending upon burner size and amount of use. If you use a small 5MJ burner for 30 minutes per day, the gas bottle will last 81 days. If you use a large 15MJ wok style burner for 90 minutes per day, the gas bottle lasts 9 days.
How long does a 13kg BBQ gas bottle last
A 13kg cooking gas bottle will last from about 8 days to 74 days, depending upon burner size and amount of use. If you use a small 5MJ burner for 30 minutes per day, the gas bottle will last 74 days. If you use a large 15MJ wok style burner for 90 minutes per day, the gas bottle lasts 8 days.
How long does LPG last
LPG can last indefinitely as the shelf life of LPG is almost unlimited. The only limiting factor is the gas bottle itself. Assuming it is taken care of and not allowed to rust, it could last 20 years or more. Elgas gas bottles are periodically inspected to ensure the product you use is in top working order for optimal energy efficiency. If your LPG gas bottle is faulty or you have any concerns, contact Elgas and we will get the problem sorted straight away.
As an authorised gas supplier, Elgas ensures your 45kg LPG gas bottle is in top working order. We periodically test the gas bottle regulator, hoses, connectors and the bottle itself. We also partner with highly qualified gas fitters who can recommend the right type of gas and gas bottle sizes for every application.
How long does a gas bottle last for hot water
The gas supply from a 45kg gas bottle used solely for hot water can last more than 100 days. You can extend the lifespan by using water-saving shower heads and limiting the duration of your showers. If yours is a larger family and you also take baths long showers, gas consumption will naturally be much greater.
Calculations based on MJ/hr or BTU/hr
Gas appliances energy consumption is rated in MJ/hr or BTU/hr.
Gas bottle energy content is expressed in MJ or BTU.
By dividing the MJ consumption into the gas bottle MJ content, you get the number of hours that the gas bottle will last. The same is true for BTUs. Multiply the results by 1.044 (4.4% more) for a 47kg propane gas bottle.
Important reference information
To get started, here are some numbers you will need to know for your reference:
Energy equivalent conversion:
1kW/hour = 3.6MJ
1kg of LPG = 1.96 litres of LPG (propane)
LPG – propane – contains approximately 25MJ per litre
A 45kg gas bottle contains about 88 litres of LPG or 2200MJ of energy
How to use less gas at home – efficiency matters
It’s all about the appliance efficiency ratings. MJ inputs and kW outputs are directly related but are affected by the efficiency of the appliance. For example, a 25MJ heater with a 5.8 Star energy rating has an output of 6.2kW.
Now, if you do the maths, dividing 25MJ ÷ 3.6MJ, you would expect that the output to be 6.94kW, not 6.2kW. The difference is that, at 5.8 Stars, the heater is 89.3% efficient.
No gas appliance is 100% efficient, which is why we have the Star rating system to judge the relative performance of different models.
LPG/Propane shouldn’t be confused with Butane. Although both are flammable hydrocarbon gases, Butane has a higher boiling point and is more commonly used as a fuel, propellant, or refrigerant.
Heater LPG gas consumption calculation
A 15MJ 5.8 Star gas heater running at its maximum setting will last approximately 147 hours on a 45kg gas bottle based on the LPG gas consumption calculation. We know this because the 45kg gas bottle contains 2200MJ. The math is as follows: 2200MJ ÷ 15MJ = 147 hours.
However, this same heater, when set on low, consumes 6.0MJ. So, if you operate it on low only, it will last 367 hours (2200MJ ÷ 6MJ = 367 hours). As most people would vary the settings, depending on the temperature, the gas bottle will last some duration between 147 and 367 hours.
If you use your heater for four hours every evening, you would expect your gas bottle to last anywhere from 37 to 92 days.
Hot Water LPG gas consumption calculation
A 16L/min 130MJ 5.0 Star continuous flow hot water heater running at full capacity will last for 16.9 hours of actual run time on a 45kg gas bottle based on the LPG gas consumption calculation. This equates to about 204 five minute showers.
However, the water heater can run at a flow rate of as little as 3.5L/min. When running slower, the unit will self-modulate and consume less gas. This would increase the run time by roughly 4X or to about 68 hours, equating to around 816 five minute showers.
Assuming you use hot water for other things as well, totalling 20 minutes per day at maximum, your gas bottle would last about 50 days.
Cooktop LPG gas consumption calculation
Cooktop burners are an even greater challenge to calculate. The burners on a particular cooktop could vary from 5MJ for the smallest burner to 9MJ for a medium burner, 12MJ for a large burner and 15MJ for a wok burner.
Add to this the fact that each can be run at less than maximum and you can see the maths challenge. If you use the medium 9MJ burner as the average, you get 244 hours of cook time on a 45kg gas bottle, based on the LPG gas consumption calculation.
Not surprisingly, many Elgas customers report that a single bottle can last more than a year.
LPG Gas consumption calculation for multiple appliances
Now the math gets really challenging. You really can’t add the MJ ratings of all of the appliances together, as they would rarely be used all at the same time and for the same duration. The easiest method of calculating is to estimate how long you use each appliance per day and total their daily consumption.
Using the previous appliance examples:
- You use your hot water for 20 minutes per day on maximum. This equals 43MJ of consumption.
- You use your heater on maximum for 4 hours every evening. This equals 60MJ of consumption.
- You cook using one medium 9MJ burner on maximum for 45 minutes per day. This equals 7MJ of consumption.
- Adding these all together, you are using 110MJ per day. Based on this, you would expect a 45kg gas bottle to last for approximately 20 days. (2200MJ ÷ 110MJ = 20), based on the LPG gas consumption calculation.
You may also wish to see:
How Much Gas is Left in the Gas Bottle
Tips for Not Running Out of Gas
How long does a gas bottle last in a heater – A 9kg example
A typical patio heater would be about 35MJ (33,173 BTU). Since a 9kg gas bottle has 441MJ (417,987 BTU) of energy content, a gas bottle will last 12 hours in a heater rated at 35MJ. How long a gas bottle lasts in a heater depends on the burner size.
45kg gas bottle LPG consumption calculation chart
For those who can’t be bothered with the maths, here is a quick LPG gas consumption calculation chart
Remember to multiply the LPG Gas Consumption Calculation Chart by 1.044 (4.4%) for a 47kg propane gas bottle.
Gas Consumption = MJ
Megajoules per Hour (MJ/hr) ratings on appliances actually indicate the gas consumption of the appliance, not the heat output. It is often expressed as just MJ. On the other hand, heat output must also take into account the relative energy efficiency ratings of the models being compared.
Heat Output = kWh
Kilowatt Hour (kWh) is how gas heater output is measured. 3.6 MJ of input equals 1kWh of output at 100% efficiency. However, no gas appliance is 100% efficient. That’s why we have Star Ratings, so we can compare relative efficiency between models. Appliance output is often expressed as just kW.
Energy Efficiency – Star Ratings
Star ratings were developed to provide consumers with an easy way of comparing the energy efficiency of different models of gas heaters and hot water systems. All states in Australia now require both LPG and Natural Gas heaters to be tested and certified, under AS4553, by independent testing organisations, such as the AGA and SAI Global.
The Star Rating is based on net heater efficiency. Net heater efficiency is calculated on the basis of a combination of efficiency measures and takes into account all gas and electrical inputs. It basically compares the amount of raw energy input consumed by the heater in comparison to the heat energy output provided.
This is calculated as a percentage and then translated into the corresponding Star Rating. Please see Energy Efficiency & Star Ratings for Gas Heaters
Comments, questions or feedback?
Please Email us at: [email protected]The information in this article is derived from various sources and is believed to be correct at the time of publication. However, the information may not be error free and may not be applicable in all circumstances.