The withdrawal volume from a gas cylinder depends on a number of parameters, for example the duration of the withdrawal and the size of the cylinder. In this article, we will give you an overview of how much LPG comes out of the cylinder in different withdrawal scenarios for the cylinder sizes commonly used in Germany.
How much gas do I actually get from my cylinder—and how long will it last under continuous operation? Many users—whether campers, grillers or technicians—underestimate how strongly the withdrawal rate of liquefied gas depends on external factors. Although every gas cylinder states a filling mass, that does not tell us how much energy per hour is actually available. What matters is not only the cylinder size, but also the withdrawal duration, the ambient temperature and, to a lesser extent, the cylinder’s design or material.
In this article we show, using practical values, what withdrawal masses are realistic for 5 kg, 11 kg and 33 kg cylinders, how the output changes during continuous operation, and why cylinders may ice up under high demand. It is ideal for anyone who wants to reliably plan for grilling, heating, cooling or commercial use.
Whether for grilling, heating or cooling—many users are occasionally surprised that the gas appliance “weakens” even though the cylinder is not empty. The reason lies not in the content, but in the physical processes when transitioning from liquid to gas.
Liquefied gas, a mixture of propane and butane (or in cylinders and cartridges often in nearly pure form), is under pressure in liquid form in the cylinder. When the valve is opened, a portion of the gas evaporates—this process absorbs heat from the surroundings. The higher the withdrawal rate, the faster the cylinder cools. That can lead to the evaporation slowing—and the usable gas per hour dropping significantly.
The gas type also plays a role: butane has a significantly higher boiling point than propane. While propane still evaporates even at –40 °C, the limit for butane is already around 0 °C. If the mixture is rich in butane, the withdrawal performance drops noticeably at low temperatures.
A typical warning signal: icing of gas cylinders. This shows that the demand exceeds the evaporation capacity—especially with smaller cylinders, undersized cylinder installations or a cold environment.
The actual withdrawal rate from a gas cylinder depends on several factors. Even with identical filling mass, the usable performance may differ significantly depending on the circumstances. For reliable planning—whether for heating, grilling or workshop use—it is worthwhile knowing these influencing factors:
How much liquefied gas can actually be withdrawn depends—as described—strongly on external factors. Nevertheless, typical practical values can be given as orientation for various use cases.
From the smallest propane‑butane cylinder, surprisingly much energy can initially be withdrawn: in the short term it can deliver about 1.5 kg of liquefied gas per hour, corresponding to a power of about 19 kW. With increasing withdrawal duration, however, the performance drops significantly. During extended use, only about 0.2 kg per hour is available—this corresponds to about 2.6 kW.
From the 11 kg cylinder—which is more than twice as large—one can withdraw a striking amount of energy in the short term: up to 2 kg of liquefied gas per hour, corresponding to about 25 kW. During longer or continuous withdrawal, however, this output declines continuously. For long-term use, one should expect a continuous output of about 4 kW.
With its nearly three to six times filling mass, the 33 kg cylinder is the largest commonly available variant in Germany. For short withdrawal, one can expect up to 3 kg per hour—this corresponds to about 40 kW. During extended, steady use, however, the cylinder still delivers a respectable continuous output of nearly 8 kW.
A heater of 5 kW consumes about 0.39 kg of liquefied gas per hour. From this it follows:
These values apply under ideal conditions (e.g. ambient temperature above 15 °C). If the temperature drops or the device is used continuously, the withdrawal mass may fall significantly—especially for small cylinders.
In some applications one may reach the physical limits of a cylinder—especially under long or intense withdrawal. The most frequent consequence: the cylinder ices up externally, performance drops and the connected appliance operates unreliably or shuts off. With a few simple measures one can counteract or prevent this:
🚫 What you should never do:
Many users choose a gas cylinder based only on the filling mass or size. But for the actual use of a gas appliance—grill, heater or commercial consumer—the short‑term and continuous withdrawal rates can be decisive. They determine how much power per hour is available, and depend heavily on cylinder size, ambient temperature, withdrawal duration and appliance load.
Anyone who wants to plan reliably should not rely on theoretical values alone, but understand the physical limits of the cylinder—especially in continuous operation or at low temperatures.
This blog will never ask members of the public or unqualified persons to make changes to or fiddle around with technical systems themselves.
In accordance with the Industrial Safety Regulation (BetrSichV), a qualified person must take care of a system which requires monitoring.
A qualified person is someone who has the specific specialist knowledge required. This knowledge is gained by way of a professional apprenticeship, corresponding professional experience or current occupational activity.
Please note that the texts are based on information, regulations and standards for Germany. Please always check the rules and regulations in the relevant country of destination and consult specialists if necessary.
