Oxygen Not Included Wiki

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Oxygen Not Included Wiki
This article has not been revised for the current version (U40-494396). It was last updated for AP-398142. It may contain inaccuracies.
This article has not been revised for the current version (U40-494396). It was last updated for AP-398142. It may contain inaccuracies.

A Self-Powering Oxygen Machine (SPOM) is an engineering construct which produces Oxygen as well as additional power which is used to support it.

The Elements[]

  • The key element is the Electrolyzer, which consumes water and produces Oxygen and Hydrogen.
  • Gas Pumps are used to siphon both gases out; at least two are needed per Electrolyzer or it will be constantly overpressured.
  • One or multiple Hydrogen Generators are used to convert the Hydrogen into Power.
  • Gas separation is done either by using a Gas Filter or by utilizing the fact that Hydrogen is less dense than Oxygen (i.e. it rises up).
  • A kickstart and reserve generator, e.g. a Coal Generator.
  • Some kind of cooling to prevent the Electrolyzer(s) and the Hydrogen Generator(s) from overheating, such as an Anti Entropy Thermo-Nullifier or a bunch of Wheezeworts. Cooling is typically not needed if all elements are made of Gold Amalgam; the SPOM can then be self-cooled.


  • Geysers are a renewable source of water that can often easily support a SPOM. Use the Geyser Calculator to easily find out how much water one produces and how many Electrolyzers it can support. Note that Salt Water needs to go through a Desalinator first, which outputs only 93% of its intake Salt Water mass as Water. ( (4650g/s) / (5000g/s) = 0.93 = 93%)
  • Due to the high output temperature of Oxygen of an Electrolyzer (70+ °C), it is a good idea to cool the produced Oxygen before releasing it into a base. Coolers typically use a Steam Turbine - Thermo Aquatuner heat deletion device.
    • As an alternative non-permanent solution, the SPOM can be built in or near a cold biome with radiant pipes running through that biome before piping to the base.
  • Some SPOMs produce excess Hydrogen, which can be used as an auxiliary power source or to power an Anti-Entropy Thermo-Nullifier.

Simple setup[]

The simple setup uses two Gas Pumps and filters out Hydrogen with a Gas Filter. It occasionally needs a power injection; the Hydrogen Generator cannot power it by itself. Buildings in the upper chamber will overheat if not made from Gold Amalgam. It will also leak heat through the Manual Airlock and the Pneumatic Doors.

Basic SPOM[]

A efficient, basic, self-filtering SPOM.

The initial startup will pump the wrong element, which will cause damage to the hydrogen generator. Under most circumstances, this will quickly set itself up to only have the correct gasses pump.

The primary benefit of this design is that all components run under a single 1k wire. It also produces a small amount of excess hydrogen, which allows for external power usage.

View Blueprint on BlueprintNotIncluded Icon: Switch overlay

Mouse-wheel: Zoom

Right-click and drag: Move view

Setup with an environmental gas filter[]

A more complex setup is to use three Gas Pumps: two for the Oxygen and one for the Hydrogen and exploits the fact that the tile can hold only one type of gas at the same time. Additionally it uses an Atmo Sensor to extract only some part of hydrogen and maintain enough pressure so that no oxygen passes the filter. The empirical best value for the Atmo Sensor is Activate if above 600 g.

Besides being more difficult, more expensive and having more complicated maintenance this setup also requires a 'purging' phase to start proper separation. Also, even in the normal working mode it lets a bit of hydrogen into the oxygen pipe (be aware of that if you plan to use it for Atmo Suits). However, once it's been installed, it works perfectly, netting 600-650 kg of oxygen per cycle, sometimes more.

It is also possible to build this with Insulated Tiles instead of regular Tiles and Metal Tiles. However, this machine will then leak heat from the Mechanized Airlocks and buildings will have to be constructed from Gold Amalgam to prevent overheating.

External links[]