Outside, you live on what is inside your suit. This article explains how the air canister, waste tank and filters work together, how to fill canisters without them bursting, and how a chip in the Hardsuit warns you in time. All values come from Stationeers 0.2.6428.
What your lungs need
According to the game data the character's lungs hold 6 litres and breathe oxygen. How well that works depends on the oxygen partial pressure: breathing efficiency is the partial pressure divided by 16 kPa, clamped to 0 to 1.5. From 16 kPa you breathe fully; with no oxygen at all you take damage after about 7.5 seconds.
Three more limits apply:
| Limit | Value |
|---|---|
| total pressure | 20 to 607.95 kPa |
| toxic gases | warning from 0.5 kPa, damage from 1 kPa partial pressure |
| breathing air temperature | lung damage below −10 °C and above +50 °C |
Carbon Dioxide is not a poison in the game. But it displaces oxygen: as its share in the suit air rises, the oxygen partial pressure drops.
How much you use and breathe out
According to the game code the character takes up to 0.0048 mol of oxygen per tick (0.5 s), times breathing efficiency and times a difficulty factor: Easy 1, Normal 2, Stationeer 4, Creative 0. Half of it is breathed out again as carbon dioxide – with the helmet closed into the helmet air, which mixes with the suit air, otherwise into the room. That is why the starting kit has three carbon dioxide filters in the suit.
A worked example on Normal at full breathing efficiency: 0.0048 · 2 = 0.0096 mol per tick, so about 69 mol of oxygen and 35 mol of carbon dioxide per hour. The starting canister with 150 mol of pure oxygen therefore lasts a little over two hours. If the oxygen partial pressure is 24 kPa or more, breathing efficiency rises to 1.5, and the same canister is empty after just under an hour and a half. Leaks and filter operation come on top.
The three building blocks
The Eva Suit and the Hardsuit share the same basic layout:
| Slot | Job |
|---|---|
| 0 Air Tank | gas canister with breathing gas |
| 1 Waste Tank | gas canister for whatever has to leave the suit air |
| 2 Life Support | battery cell |
| Filter | Eva Suit slots 3 to 5, Hardsuit slots 4 to 7 |
Suit and helmet hold 13 litres together. That is the buffer when the air canister is empty: at 101 kPa and 20 °C just 0.54 mol.
For the waste tank the suit has its own upper limit of 4,053 kPa. The canister itself withstands 10,132.5 kPa – so the suit's limit kicks in long before. Swap the waste canister in good time and carry an empty spare.
Pressure and temperature in the suit
According to the game code the suit regulates its internal air to two set points. On the Hardsuit you read and write them via logic, on the Eva Suit only with the buttons:
| Set point | Logic value | Default | Range via the buttons |
|---|---|---|---|
| internal pressure | PressureSetting | 101.325 kPa | 0 to 202.65 kPa in 1 kPa steps |
| internal temperature | TemperatureSetting | 293.15 K (20 °C) | 273.15 to 333.15 K (0 to 60 °C) in 1 K steps |
If the internal pressure is below the set point, gas flows in from the air canister – on the Hardsuit you switch that with AirRelease. If it is above, the suit pushes gas through the filters into the waste tank (Filtration); that costs 10 J per tick from the battery. Heating and cooling also run on the battery: heating costs half the heat added, cooling only 1 % of the heat removed, and the removed heat ends up in the waste tank. Without a waste tank, or from 4,053 kPa in it, the suit no longer heats, cools or filters. A damaged suit regulates more weakly, because its output drops with damage.
Via IC10 the Hardsuit checks no limits. Always write TemperatureSetting in kelvin and stay within the button range. With Flush on the helmet you blow the air out of helmet, suit and lungs at once; afterwards the air canister refills it.
What goes into the air canister
Only the oxygen partial pressure counts. Pure Oxygen does the job, and so does a mix with Nitrogen – nitrogen is neither fuel nor poison. A good base is Ice (Oxite): one piece releases 22.5 mol of oxygen and 2.5 mol of nitrogen when it melts, so 90 % oxygen.
Work out the mix beforehand. With 30 % oxygen you need at least 16 / 0.3 ≈ 53 kPa total pressure to breathe fully. With 90 % even 18 kPa would do – but then you run into the lower limit of 20 kPa total pressure.
Filling canisters safely
Canisters are filled from a pipe network. The Gas Tank Storage connects a canister to a gas pipe and reports pressure, temperature and gas fractions through logic. The Portable Gas Tank with 790 litres also has a slot for a canister.
Never fill to the limit. Pressure rises with temperature, and above the limit a canister takes damage after more than 5 ticks and bursts. A good rule of thumb is 75 % of the limit at 20 °C:
| Canister | Volume | Limit | 75 % | Contents at 20 °C |
|---|---|---|---|---|
| Canister | 64 L | 10,132.5 kPa | 7,600 kPa | ≈ 200 mol |
| Gas Canister (Smart) | 64 L | 20,265 kPa | 15,200 kPa | ≈ 399 mol |
| High Volume Gas Canister | 83 L | 25,331 kPa | 19,000 kPa | ≈ 647 mol |
Calculated with n = p · V / (R · T), for example 7,600 · 64 / (8.3144 · 293.15) ≈ 200 mol. Why the headroom matters: a canister at 7,600 kPa and 20 °C already has 7,600 · 373.15 / 293.15 ≈ 9,674 kPa at 100 °C – still below the limit. Filled to 9,000 kPa it would be 11,456 kPa, and the canister bursts.
Filters
There is a filter for every important gas, 16 kinds in total – from carbon dioxide via pollutant and volatiles to hydrochloric acid and silanol. Each kind comes in four durability grades:
| Grade | Example | Made in |
|---|---|---|
| Normal | Filter (Carbon Dioxide) | pipe bender, tier 1, iron |
| Medium | Medium Filter (Carbon Dioxide) | tier 1, iron, silver, constantan |
| Heavy | Heavy Filter (Carbon Dioxide) | tier 2, steel, invar, Stellite |
| Catalytic | Catalytic Filter | no recipe |
Fit filters for the gases that have no business in your suit air. Which those are, the Hardsuit shows through RatioCarbonDioxide, RatioPollutant and the other fractions, or the tablet with the Cartridge (Atmos Analyzer). On Vulcan, where the outside air consists of volatiles, pollutant, CO2 and hydrogen, Filter (Methane) and Filter (Pollutant) belong in the basic kit.
The Gas Mask uses the same filters but has no canister. It only helps where the surrounding air is already breathable apart from a few gases.
A watchdog chip for the Hardsuit
The Hardsuit has a chip slot. The chip addresses the suit as db, because the suit is its housing. Through the slot values it reads the pressure of both canisters and the battery charge, and plays a warning sound via SoundAlert. The most important warning comes last and wins.
# Hardsuit watchdog: alert on low air, full waste tank, weak battery
define AIRMIN 1000 # kPa air tank below: warning
define WASTEMAX 3500 # kPa waste tank above: warning (limit 4053)
define BATTMIN 0.2 # battery below 20 %: warning
define SAIR 0 # slot 0: air tank
define SWASTE 1 # slot 1: waste tank
define SBATT 2 # slot 2: life support
define QUIET 0 # Sound.None
define SNDBATT 23 # Sound.PowerLow
define SNDWASTE 39 # Sound.PressureHigh
define SNDAIR 40 # Sound.PressureLow
alias air r0
alias waste r1
alias batt r2
alias sound r3
alias flag r4
start:
yield
move sound QUIET # default: no sound
ls batt db SBATT ChargeRatio # charge 0 to 1
slt flag batt BATTMIN
select sound flag SNDBATT sound
ls waste db SWASTE Pressure
sgt flag waste WASTEMAX
select sound flag SNDWASTE sound
ls air db SAIR Pressure # last: most important warning
slt flag air AIRMIN
select sound flag SNDAIR sound
s db SoundAlert sound
j startWhat you can adjust: AIRMIN, WASTEMAX and BATTMIN. Keep WASTEMAX clear of the suit's limit of 4,053 kPa. The sound numbers come from the game's Sound. list. More on define and alias in the IC10 Academy, on slots in the Slots lesson.
Checklist before heading out
- Air canister full, spare canister in the backpack.
- Waste canister empty or nearly empty.
- Battery cell charged, spare along.
- Filters fitted to match the outside air.
- On hot worlds: canisters not filled to the limit.
Next
- Suit and equipment: what you wear on your body – all suits, helmets and back items compared
- Survival: the first minutes – the basics after landing
- Atmosphere and pressure – gas equation and partial pressure in depth
- Try the code right away: IC10 editor