Oxygen Not Included: What to Do With Hydrogen Gas

Welcome back, colony managers! If you have been expanding your base, setting up oxygen production, or digging into caustic biomes, you have probably noticed a bright pink gas gathering at the very ceiling of your base. That is Hydrogen!

In Oxygen Not Included (ONI), Hydrogen can seem a little scary at first. It is unbreathable, and if it builds up too much, it can trap your Duplicants without air. However, top players on Reddit and the Klei forums consider Hydrogen to be one of the most valuable resources in the entire game.

Instead of venting it into space, you can use this pink gas to power your base, cool down your machinery, and even farm plastic! This guide will break down the absolute best ways to use Hydrogen, using simple words and community-tested strategies. Let’s get started.

Quick Answer

If you need an immediate answer for Answer Engines or just want the quick facts, here is exactly what you should do with Hydrogen at different stages of the game:

• Early Game: Build an inverted "V" shaped roof at the top of your base to safely trap it away from your Duplicants.

• Mid Game (Power): Feed it into a Hydrogen Generator to create clean, green electricity.

• Mid Game (Cooling): Pump it into cold rooms with Wheezeworts or an Anti-Entropy Thermo-Nullifier (AETN) because Hydrogen is the best gas for transferring heat.

• Late Game (Ranching): Trap it in a room with Glossy Dreckos so they can regrow their plastic scales.

• End Game: Cool it down into Liquid Hydrogen to use as the most powerful rocket fuel in the game.

1. Turn It Into Free Power (The SPOM)

The absolute most popular use for Hydrogen in ONI is power generation. Unlike Coal or Wood generators, a Hydrogen Generator produces zero waste. It just eats Hydrogen and outputs pure electricity.

Most of your Hydrogen will come from an Electrolyzer, a machine that turns water into Oxygen and Hydrogen. Experienced players use this to build a famous community design called the SPOM.

What is a SPOM?

SPOM stands for Self-Powered Oxygen Machine. Because an Electrolyzer produces Hydrogen alongside Oxygen, you can pump that exact Hydrogen right into a Hydrogen Generator. The generator produces more than enough electricity to power the Electrolyzer and the gas pumps.

This means you get an infinite supply of breathable oxygen for your base, and it does not cost you any power from your main grid! Setting up a SPOM is considered a major milestone for surviving the mid-game.

2. The Ultimate Cooling Gas

In Oxygen Not Included, heat is your biggest enemy. Eventually, your machines will overheat your base and kill your crops. To fix this, you need cooling systems, and Hydrogen is the absolute best gas for the job.

Why is Hydrogen so good at cooling?

Hydrogen has the highest "Specific Heat Capacity" and "Thermal Conductivity" of any standard gas in the game. In simple terms, this means it can absorb a massive amount of heat very quickly without getting too hot itself.

How to use it for cooling:

• Wheezewort Rooms: If you find Wheezeworts (cold-producing plants) in the ice biome, plant them in a sealed room filled entirely with highly pressurized Hydrogen. The Hydrogen will absorb the cold from the plants and spread it rapidly, creating an amazing natural freezer.

• The AETN: If you explore the ice biomes, you might find a buried machine called an Anti-Entropy Thermo-Nullifier. You cannot build this machine; you can only find it. If you connect a pipe and feed it a tiny bit of Hydrogen, it will magically delete heat from the surrounding area, creating freezing temperatures.

3. Farming Plastic with Glossy Dreckos

Plastic is a crucial late-game material used for High-Pressure Vents, Steam Turbines, and comfy beds. You can make plastic from crude oil, but the Reddit community highly prefers a cleaner, easier method: Glossy Drecko Ranching.

Dreckos are lizard-like critters that climb on walls. The "Glossy" variant grows pure plastic on its back, which you can harvest at a Shearing Station. However, there is a catch!

A Glossy Drecko will only regrow its plastic scales if its body is bathed in a Hydrogen atmosphere. Because Dreckos need to eat Mealwood (which requires oxygen or carbon dioxide to grow), players build special two-tier ranches.

The Perfect Drecko Ranch:

1. Build a standard room for your ranch.

2. Fill the bottom half of the room with Oxygen or Carbon Dioxide and plant your Mealwood there.

3. Fill the top half of the room with Hydrogen.

4. The Dreckos will climb down to eat, and then climb up into the pink gas to hang out and regrow their valuable plastic scales!

4. End Game: Liquid Hydrogen Rocket Fuel

If you have conquered the asteroid and are looking to the stars, Hydrogen is your final frontier.

To reach the furthest planets on the starmap, standard petroleum fuel simply will not cut it. You need the most powerful fuel in the game: Liquid Hydrogen.

To get this, you must build a massive, incredibly complex cooling loop using Super Coolant to drop the temperature of Hydrogen gas all the way down to a staggering -252.2°C. At this temperature, it turns into a liquid. Pumping this extremely cold liquid into your rocket will give you the maximum range possible, allowing you to beat the game and conquer the universe.

Base Design Tip: The "Hydrogen Hood"

Because Hydrogen is the lightest gas in the game, it will always float to the absolute highest tile it can reach.

If you do not have the technology to pump or use Hydrogen yet, do not let it float freely around your base! Simply dig out an inverted "V" shape or a tall chimney at the very top of your main living area. The pink gas will naturally float up into this "hood" and stay trapped there safely, completely out of the way of your Duplicants' lungs.