Oxygen Guide (how to breathe)

Having issue with oxygen in Oxygen Not Included?
"Game is working as intended", Klei Dev.

Introduction

People say you can't live without love.. But I think oxygen is more important.

Oxygen is a breathable gas and required by duplicants to survive. They breath in oxygen and exhale carbon dioxide. If the pressure is sufficient/high they will breath normally, if it is low or unbreathable (toxic) they will hold their breath from time to time (dupes will show breathing bar below their health). And if they are running out of oxygen, they will stop any task and will run to the closest breathable area. If their breath meter reaches zero, they will suffocate to death.

Oxygen is lighter than carbon dioxide, this is way O2 will rise above CO2. Due to this fact, it's highly recommended to build a carbon pits below your base to prevent them from filling your living area (which can be potentially destructive if happen).

This is the list of current gases in the game, from light to heavy:
1. Hydrogen (pink)
2. Polluted Oxygen (green-yellow)
3. Oxygen (light blue)
4. Natural Gas (orange)
5. Chlorine (light green)
6. Carbon Dioxide (black)

How to create Oxygen

Oxygen can be produced by machines, currently there are 4 ways to create oxygen, they are either through generation or conversion.

Oxygen Generation/Conversion:

• Algae Deoxydizer
  Uses algae and power to create oxygen. It takes 550g algae & 120W per second, produces 500g Oxygen per second.
  This may seems efficient at the start, but actually the conversion rate of the algae is not great. As you progress, you will soon notice that you won't have enough algae to sustain your colony.
  
  
• Algae Terrarium
  Unlocked via farming tech, uses algae and water to convert Carbon Dioxide back to Oxygen. It takes 30g algae, 300g water & 333.33mg CO2 per second, produces 40g Oxygen per second.
  This have better algae conversion but took quite a lot of water and require a lot of attention from your dupes.
  
  Dupes will have to refill both the algae & water, this can occupied the dupes time and hinder your colony progression. Also Terrarium has a slow O2 production. Instead of steady O2 production, this is more of an early solution to clear out CO2.
  
  
• Electrolyzer
  Unlocked via Percolation tech, uses 1000g water & 120W per second, produces 888g Oxygen & 112g Hydrogen per second. Required Liquid Piping.
  This is the best O2 generator to date. You need to move on from algae conversion and setup Electrolyzer asap for a much better O2 production.
  
  Besides the Electrolyzer machine, you also need a working Liquid Pump and Piping to deliver the clean water. I'll discuss it later.
  
  
• Air deodorizers
  Unlocked via Sanitation tech, uses Filtration Medium (Sands) to convert Polluted Oxygen to Clean Oxygen. It takes 1000g Filtration Medium and convert 100g PO2 to produce 50g O2 & 500g Clay per second.
  This is not a solution for your O2 generation, the main purpose of this is to clean/purify PO2 from your base.

How to Floor

Before we start talking about how to setup a proper oxygen generation, first we need to have a proper interior architecture. A good design will have a good air flow.





Dupes can jump 1 tile away (vertically), so I usually have a 1 tile gap between the ladder and floor tile. This is to let the air flow faster between floor. Once you can create Gas Permeable or Mesh Tile, you can also use them to fill the gap. Both tiles let air flow through them (Mesh also let water through).








Besides the ladder area, you also need to create an air flow between the floor itself. I usually use Gas Permeable Tile for this. Why not using Mesh Tile? because I don't want to make a mess (pun intended). Mesh Tile allow water to go through them, so if there is a leak from pipes, wall, etc or a dupe vomit or pee on their pants, those polluted water could go everywhere. It will be hard to mop all of the water and even worst, polluted water could reach your clean water reservoir. So it's better to contain the leak at 1 floor only. For this purpose, i usually raise the floor 1 tile higher at the end of the floor (near the ladder).

You can add door too, for aesthetic or intended purposes (seal room temperature/pressure).

Algae Deoxydizer

Algae Deoxydizer have maximum pressure limit, when the air pressure near them reach 1800-2000g/tile, they will stop working. Which is why building them close to each other will reduce they efficiency. So spread them out.

Even in my example they are still too close. Well, it's just to give you a better picture of what i meant.

Algae Terrarium

If you already have a good air flow system in your base, CO2 will always go down to the bottom of your base. That's why it's a good place to put your Algae Terrarium. Beside going down, CO2 also tend to go right. So it's also a good idea to put some in the bottom right corner of your base.

Electrolyzer

Same with Algae Deoxydizer, Electrolyzer also have maximum gas pressure. So it's better to spread them out.




Unlike the 2 previous buildings, Electrolyzer require more setup before you can make it works.
Beside electricity, you also need a liquid pump that is connected to the Electrolyzer using liquid pipes.

White Socket is for intake, Green is output. So you connect the green output from the liquid pump to the white intake of the Electrolyzer.

Don't forget to connect the power :)








Green is for Output, it means gas will flow from there.
White is for Intake (input), it means gas will go in there.

In a nutshell, green goes to white.
So, to setup up something or if you want to connect something, you just need to build pipes from green to white.



In the example, gas will flow from the Gas Pump to Thermo Regulator through its Intake (White), and after that the gas will get pumped out through the Thermo's Output (Green) and goes to the vent (Intake/White)

Side note: Thermo Regulator cools the Gas piped through it, but outputs Heat in its immediate vicinity.


Same with Gas Plumbing
Green is for Output, it means liquid will flow from there.
White is for Intake (input), it means liquid will go in there.

Some machine has both intake & output, make sure you are not connecting the pipe to the wrong hole ( ͡° ͜ʖ ͡°)
If you connect Green to Green or White to White, they won't work.
If you connect the wrong gas/liquid, the machine will break.


In the example, liquid will flow from the Liquid Pump to Lavatory through its Intake (White), and emitting polluted water through its Output (Green) and goes to the vent (Intake/White)

Side note: Lavatory is a toilet, it hygienically handling Duplicant waste.

There are 3 ways to setup Electrolyzer. You can pick one of them, both have pros & cons.

The First One

Build a base that has pyramid or triangle shape ceiling (similar to house).


You put a gas pump at the top of your ceiling and build the Electrolyzer at the bottom or second floor of your base (because the bottom of the base are for CO2 building).

The idea behind this setup is to let the air flow and fill naturally. Because Hydrogen are lighter than O2, they will always go to the top of your base, this is why you put gas pump at the top. It's to pump the Hydrogen Gas to your Hydrogen Generator. Just don't forget to put Gas Filter so you don't break the Generator. (I don't have the filter in the picture because I'm an idiot and too lazy to edit it).

The Gas Permeable Tile in the green circle are to make sure all the gas go through that floor tiles.

The pink doodle are Hydrogen Gas flow.


Tech Required:

• Liquid Piping
  
• Percolation
  
• Gas Piping (optional)
  
• Filtration (optional)
  
• Performance Combust (optional)

You can start using the Electrolyzer without having to wait till you can use the Hydrogen

Pros:

• Easy to setup
  
• Tech requirement is low

Cons:

• A bit rough design, hydrogen can still get trap between floor. (not dangerous though).
  
• If not enough O2 being produce, it won't reach the top floor or certain area.

The Second One

This is a more advanced setup for the Electrolyzer. Basically you are creating an Electrolyzer Room.



You build several Electrolyzer in a room together with Gas Pump (1 Electrolyzer could feed 2 Gas Pump). Put them in a seal room, that's why an air pressure door is needed here.

Do you need 2 floors?
Well, not really. I just want to make sure that the hydrogen won't get out from the Electrolyzer Room. That's why I have 2 air pressure door, one at the 2nd floor and one at the 1st floor (entrance).

You also need several Gas Filters to filter between Oxygen & Hydrogen.


In the picture I use default 4 tiles height for the Electrolyzer Room, actually you can make the room higher to give them some space, smaller room tend to heat up faster.


Gas Pipe Layout
Gas Filter, white socket is for intake (connect it to your gas pump). Orange is output for your selected filtered gas, example if you set it to O2, O2 gas will go out through the Orange output.

The setup here is: pink is for Hydrogen, Blue are for O2.

Why so many gas filter?
Gas filter has maximum storage and takes time to filter the gas. They tend to create a bottleneck where the gas pump will stop working because the pipes are full. This is the main reason why you build extra gas filter.
Side note: usually 1 gas filter is enough for 2 gas pump.

Gas Flow
This is to show you how the air will distribute through out the base.
It needs more gas piping works, you have to build gas pipes and vent through out your base (or rooms that you want to be filled with oxygen).
The pump will take both Hydrogen and Oxygen gas, and it will be filtered. O2 will go to your room, hydrogen will go to your Generator. While the other gas will go to your CO2 pit.

Since you won't be using Gas Permeable Tile in the Electrolyzer Room, it's recommended that you have a hole or air vent in the right side of your Electrolyzer Room to let the CO2 sink.
This only apply if you build the room inside or on top of your CO2 pit.

Tech Required:

• Liquid Piping
  
• Percolation
  
• Gas Piping
  
• Filtration
  
• Performance Combust (optional)

Pros:

• Neat setup. Hydrogen won't get stuck around your living quarter/base
  
• O2 distribution is more equal and can be focused in certain area (heavy populated or activities)

Cons:

• A bit harder to setup, also required more time (lots of gas piping)
  
• Require more tech
  
• Gas flow can took longer to reach certain area
  
• Use more power than the previous setup

The Third One

This is my latest and current setup that I use. Bassicaly it's a hybrid between the two previous setup.

As you can see from the picture, I use Gas Permeable tiles and higher ceiling in the room.
The gas Permeable is so that O2 will fill the bottom floor and higher ceiling is so that there is room for the hydrogen to go up and seperated quite far from the O2 that will be sucked by the gas pump in the bottom floor.



You can also put extra Wheezwort to chill down the O2 before being distribute outside.
This setup require bigger room but less power if you optimize them.
Also because it require less filter, which sometime block and cause traffic in the gas pipe, this setup actually distribute O2 faster than the second setup.
You just need one filter for the top gas pump to make sure that only Hydrogen goes to your generator.

Tech Required are the same as second setup
Pros & Cons are pretty much the same as second setup.

Air Deodorizers

Since the main purpose of this building is to purify Polluted Oxygen. The best place to use it is in the airlock room between your base with the outer world.

Whenever PO2 goes in to the airlock room, they will be purify and won't polluted your base.

Info, Tips & Tricks

• Air Scrubber
  This is your replacement for Algae Terrarium. Unlike Terrarium where need dupes attention in order to work. Air Scrubber can works on its own as long as it got electricity and a working pump + vent.
  
  This machine use 1000g Clean Water & 120W to remove 300g CO2 per second. It then emits 1000g polluted water.
  
  Connect the clean water pipe to the white socket (intake), and connect the green socket (output) to a liquid vent. It's recommended to build a polluted water tank to store all of your colony waste.
  You then can recycle the polluted water using another machines.
  
  Like Algae Terrarium, it's better to put the at the bottom of your base, the CO2 pit.
  
  
  
  
• Atmo Switch
  Automates switching Power grids on or off based on Gas Pressure. This allow you to set certain condition where a machine should turn on or off.
  
  Example: You can build it near the Air Scrubber and set it to only active if the pressure are above 400g. Since the Scrubber is work at best when the CO2 pressure is at least 300g, it will increase your power efficiency.
  
  Another example is to connect it to your gas pump. This allow you to control when the gas pump will pumping so that they won't consuming power if there is low/no gas in the room.
  
  
  
  
• Overtime heat will build up in your base, especially when you are using hot water from the geyser. This will cause your Electrolyzer to produce hot oxygen.
  
  
• Oxylite produce Oxygen by converting their own mass.
  
  
• Polluted Oxygen
  This is breathable and works like Oxygen (allowing Duplicants to survive).
  However, PO2 has a chance of causing Diseases when the pressure/concentration is high.
  
  Similar to Oxylite, Polluted Dirt and Slime will emit Polluted oxygen by converting their own mass.
  Polluted Water and Morbs also producing Polluted Oxygen, but without loosing mass.
  Pufts can consume Polluted Oxygen and convert it back to slime (through pooping).
  
  
• Slime can be used in Bio Distiller to produce algae & polluted water.
  
  
• Diseases
  Currently diseases have no real threat and mostly can be ignore. They usually has debuffs to skills, stress condition, or sometime cancel the dupe's action/job.
  
  Current diseases in game
  • Trench Stench
    
  • Spores
    
  • Diarrhea
    
  • Incapacitated
    
  • Hypothermia

Conclusion

I'm not sure if I cover all the information about Oxygen in this guide, but I think at least all of the basic information are here. If you still have some question, please ask in the comment section.

Like always, thank you for reading :)


Changelog:
- 2017 07 20 : Add 1 more electrolyzer setup room.

[EdenStarGazer]

Thanks

[Void Master Mittens]

This guide is outdated, especially if you include the DLC. A lot has changed since 2017.

[GoofyGuy73]

another one of those seemingly simple but actually really complicated guides

[Hell's-paitrent28]

aint a pritya butnter fli herere

[True_Hero35]

how do i make artwork

[Zervo⭐]

it has been a long time since i play the game. i don't know if there is a new method to get oxygen in the game now.
but i believe water is the main source of getting oxygen in mid-late game.
since water is renewable from the geyser. you just need to find them.

they are hot water so you need some cooler/cooling method to make them warm/cool enough to live in.

[чемодан с котами]

I still don't get it, which oxygen source is replenishable? Both Water and Slime are limited.

[Arysisa]

love it

[Apophis]

directions unclear. meep stuck in slime biome

[possum lord]

WOW IT WOLD BE AWSOME IF I COLD REDE MEME I CAN REDE