Guide to Atmospherics

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This is the Guide to Atmospherics. When properly initialized, Atmosia can keep the station aired-up through nearly any emergency. Improperly initialized, it's a waste of space at best and an outright fire hazard at worst.

If you're new to the job, feel free to jump straight to the how to set up Atmos -section. If you're ready to really learn about the atmospheric system, read on. By reading this guide you will learn how to transform Atmos from a waste of space to an actually useful addition. We will go through all kinds of theory, so this may be tough, but it will also ensure you know exactly how and more importantly how Atmos works the way it does, making you ready for all kinds of situations.

Physical Characteristics of Gases

Basic Characteristics

First let’s understand some properties of gases and how they are measured. The first three of these are what you see when you use the analyzer on pipes, canisters or other: Pressure (P): Measured in kPa, kiloPascals, pressures above 750 kPa are lethal. Pressure in a room above 1000 kPa requires internals to breathe properly.

Moles (n): Moles are the amount of particles of a gas in the air.

Temperature (T): Measures in K, Kelvin, Temperature above 360 K (~85°C) and below 260 K (-13.5°C) causes burn damage to humans. Bomb making, the TEG or fusion are mostly the only desirable places for very hot gas. Canisters rupture when the air surrounding them is over 1550 K. This is also why hot gases clog the red waste pipes - they expand, allowing fewer moles to be transported.

Unseen Characteristics

These two are unseen variables typical useful for more advanced applications.

Volume (V): An unseen variable, Volume is how much the turf, canister, tank, piped or other such has space inside it. This helps dictate how much gas it can hold. Volume is essentially the 'mole divider' when converting between a canister/air pump to your tank. Having a higher volume makes space bigger. Shocking I know. For example an extended emergency oxygen tank has twice the contained air per kPa in comparison to a regular Emergency Oxygen Tank.

Image	Item Name	Volume
	Emergency Oxygen Tank	3
	Extended Emergency Oxygen Tank	6
	Double Emergency Oxygen Tank	10
	Oxygen Tank (blue/red)	70
	Plasma Tank	70
	All pipes	70
	Pipe manifold	105
	Locker	200
	Coffin	200
	Gas Pump (each side)	200
	Volume Pump (each side)	200
	Passive Gate (each side)	200
	Heat Exchanger	200
	Gas Filter	200
	Vent	200
	Scrubber	200
	Portable Scrubber	750
	Gas Canister	1 000
	Tile / turf (any area)	2 500
	Portable Pump	1 000
	Unmovable pressure tank	10 000
	Huge scrubber	50 000

Heat Capacity: Every gas mix has a heat capacity. It is calculated by taking into account the quantity of all of the gases in the air and their specific heat. Heat capacity defines how much energy it takes to raise the temperature of a gas. The normal air mix (%30 O2, %70 N2) has a specific heat capacity of about 20 which doesn't impede heat transfer very much. Fires spreads quicker in gases with low heat capacity, and slower in gases with high heat capacity.

Gas	Heat capacity
O₂	20
N₂	20
CO₂	30
N₂O	40
Plasma	200
Water Vapor	40
Hypernoblium	2000
Nitryl	20
Tritium	10
BZ	20
Stimulum	5
Pluoxium	80

Fire: An effect caused by burning plasma. It causes massive burn damage, and a strong fire will not be stopped by standard fire suits. Fire will ignite any form of combustibles in near tiles. Sufficiently hot fires use less O₂ as they rise in temperature. The ideal burn mix is: one part plasma to ten parts O₂, and with as high a temperature as can is possible.

Pipenet Components

This will be a section detailing the overall function, and some specifics, of the various pipes, pumps, and other devices. Some details will be missed, but it will provide a basis. The first instance of a device running into a unique mechanic will be explained in further length. Expand the table below to see the details.

Image	Name	Description
	Pipe	Basic component of every pipe net. Comes in varying shapes and colors. Use the RPD to place or "pick up" un-wrenched pipes or other components into it's internal buffer.
	Pressure Pump	An oddball case. Like all pumps, it separates connected pipenets if there is nothing else connecting them. Has a maximum pressure of 4500 kPa. All pumps work by pumping the contents within them to the other side, which is 200L on one side, and 200L on the other. Any pump can not pump gas that is not actually in it, which means that very large connected pipenets will have lower pump speeds. Pressure pumps work by gradually building up to its set pressure per tick. Because of this, pressure pumps slow down when approaching their target pressure, and will not quite match their pressure after a very long time, but will get very close.
	Layer Adapter	Connects the 5 different layers of pipenets. For most stations, the red scrubber network will be on layer 2 while the blue air supply pipes will be on layer 4. Default layer is 3. Pipes on different layers do not interact with one another.
	Filter	The filter is the first device that connects 3 pipenets. It can be set to a single gas, and it will dump this gas to the side it is pointing in. All gas that is not selected will continue straight forward, as the arrow is pointing in a single line. When set to Nothing, it will allow all gas through the straight path. The filter works in L/s, and as such does not experience pressure related slowdowns, however, it has a pressure maximum of 4500 kPa. When EITHER OUTPUT SIDE is 4500 kPa or above, the filter will not function, not allowing any gas to pas. That is, both in a straight line and on its offshoot, the pressure must be less than 4500 kPa.
	Mixer	The mixer also requires 3 connections to function, as the filter does. The mixer will mix the two incoming gases using the ratio the user inputs, starts off at 50/50. Node 1 is the input in a straight line with the output, Node 2 is the offshoot compared to the output. Both inputs need to have gas in them to function unless a side with gas in it is set to 100%, in which case it will function and purely let that side through. Is pressure based, with the associated properties. Also has a pressure maximum of 4500 kPa. The mixing is influenced by temperature following the ideal gas law. When one of the input sides is hotter compared to the other input, it will let less of this side's gas through, mole-wise. This will give you scuffed ratios if you do not equalize temperatures, if you need the precision, make sure they're equal.
	Volume Pump	The volume pump is similar to the pressure pump, but operates differently. It has a pressure limit of 9000 kPa. However, this limit only kicks in when the output pipenet is currently over 9000 kPa. The pump will work if the output pipenet is below 9000 kPa, even if the resulting pressure of this action would be way higher than 9000 kPa. Counter to the pressure pump, this pump works on a L/s basis. This has a 2x200L volume as well, so you pick how much of the volume in the pump is actually pumped to the other side by changing the number. Because its max speed is 200 L/s, it will always outpace and outpressure the pressure pump. Can be overclocked using a multitool, which will cause its pressure limit to be dependent on the input pipenet, which will tend to make the maximum output pressure higher. However, this will cause 10% of gas running through it to spill.
	Unary Vent	The vent will pump gas into the room it is in, depending on the air alarm settings of the room. The air alarm has two settings to worry about, External, or Internal. External works by making the vent pump gas from its connected pipenet into the room until the room, or more accurately, the tile, matches the pressure that is set. The max pressure you can configure for External is 5066 kPa, and it slows down when approaching the set limit, as pressure pumps do. Internal works by pumping gas into the room from the pipenet until the pressure set matches the pressure in the connected pipenet. Examples: a vent set to External 200 will pump gas into the room until it is 200 kPa. A vent set to Internal 300 will pump gas into the room until the connected pipenet's pressure is 300 kPa, regardless of room pressure. As such, Internal 0 will always pump at full strength. This same effect can be achieved by turning off both External and Internal. The vent has a maximum speed it can pump at, even when extremely pressurised.
	Passive Vent	An unpowered vent that equalizes the internal and external gases. Think of it as a simple open ended pipe into the atmosphere. It is not interactable and cannot be closed. It too, is not restricted by pressure as with the other vents, opening possibilities for interesting shenanigans.
	Injector	The injector is similar to the vent in that it pumps gas onto the tile it is on. However, it is not controlled by an air alarm, but rather works by hand. It is also in L/s units again, similarly to the volume pump. Also similarly to the volume pump, it is the faster one when compared to its pressure based cousin, the vent. It does not have a maximum pressure change per second, as vents do, and will always outpace them. This comes at the cost of the control that vents give you.
	Scrubber	The gas sucking cousin of the vent, which sucks gas into the connected pipenet. Scrubbers are operated using the connected air alarm. They only suck in gas that is on their tile, unless you set their range to Expanded, in which case it'll suck in a 3x3. The Scrubber sucks at a rate of 200 L/s per tile. So when put to expanded it will suck 1800 L/s if all 9 tiles are able to be sucked from. Setting them to Siphon will make them suck in every gas. If the scrubber is not on siphon, you can select specific gases for it to suck into its pipenet. The more gases are selected to scrub, the more power is used.
	Manual Valve	Acts identically to a Digital Valve, however, the manual valve does not allow silicons to operate it.
	Digital Valve	A valve that opens when clicked, and connects the two pipenets it separates when doing so. Counter to pumps, it experiences no delay in its gas transfer. It essentially acts as a pipe. Has 200L of volume on one side, and 200L on the other end. This can be operated by both carbon mobs such as humans, excluding xenomorphs, and silicons.
	Pressure Valve	An activatable valve that lets gas pass through if the pressure on the input side is higher than the set pressure.
	Heat Exchanger	Place two of these next to each other, facing each other, and they will equalize the temperature of the gases inside them. The heat exchanger is not part of the (more widely used) heat exchange pipes system.
	Heat Exchange pipes	Functions like regular pipe, however, this will attempt to equalize the temperature between the pipenet and the space it is in. This is based on heat capacity, which can be found on this page. Higher heat capacity means a gas will soak in more energy, which means it is better at cooling when cold, and better at heating when hot. These pipes commonly see use in Supermatter setups, to cool down the coolant by using these pipes in space. However, they can also be used to heat up places, of course. Has a 1K efficiency loss. Space is 2.7K, but heat exchange pipes will only cool the gas in them to be about 3.7K.
	Heat Exchange Junction	These are used to transfer from normal pipes to heat exchange pipes. These need to be between a pipe, or pump, etc. and heat exchange pipes for gas to actually be transferred between the two different kinds of pipe. While this pipe looks partially like a heat exchange pipe, it does not equalize temperature in the way that heat exchanging pipes do. It only looks like it does, so these can be safely connected to any pipe in a normal room without risk.
	Temperature Pump	A pump that transfers energy in one direction until both sides are of equal temperature.
	Temperature Gate	A valve that releases gas through if it is hotter/colder depending on its setting. Setting can be changed by using a multitool on it.
	Passive Pump/Gate	These are a combination of pumps and valves. They work up to their set pressure, with a maximum of 100 atm. These can never do more than equalize the two connected pipenets, just as valves do. However, they only work one way, rather than mixing the gas between the two pipenets perfectly as valves do. Think of them as a pressure pump that only equalizes pressure between two pipenets.

The Gases and Their Functions

Expand the table below to learn more about gases such as O₂ orTritium what they do and where they can be found in-game.

Can	Name	Description
	O₂	Oxygen. All humans, pets, and lizard-people need more than 16 kPa of oxygen in the air or internals to breathe. Any less and the creature starts to suffocate. It is required to oxidize a plasma fire. A room with 100% plasma will not burn. More oxygen causes plasma fires to increase in heat and size. Oxygen mixed suddenly with heated plasma causes explosions when in a tank. See Temperature. Oxygen is an invisible gas. To detect it, use your PDA or a wall mounted Air Alarm. Oxygen canisters are marked in blue. Emergency Oxygen Tanks, filled with about 300 kPa, spawn in your emergency Internals Box. Larger Oxygen Tanks are in Emergency Lockers all across ship, which start with about 600 kPa.
	N₂	Nitrogen. Not particularly more heat absorbant than any other gas. However, it cannot burn at all, which may slow down fires simply by taking up space. It can reduce the heat penalty on the SM, which will keep temperatures down. Can be found in Atmospherics in red canisters or through the N2 farmer.
	Air	A 1:4 gasmix of O2 and N2 (20% O2, 80% N2). The station is filled with this. Air in SS13 can be seen, strangely enough, as a 'watered down'-O2, with N2 being the water. Optimal atmospheric pressure for humans is 101.3 kPa. Due to the minimum of 16 kPa of O2, the pressure of 101.3 kPa cannot be changed too much without the situation becoming excessively lethal. Under 16 % oxygen? You start dying. Under 90 kPa due to fire from a while ago? You start dying. Be mindful of this. Air canisters, marked in white, can be found in emergency storages or through the air mix chamber in Atmospherics.
	Water Vapor	Pure H₂O. Keep away from the Clown - this slips people and even freezes tiles when released at low temperatures. The Janitor starts with a tank in his closet; created as a waste product when tritium burns.
	CO₂	What the fuck is Carbon Dioxide!? It's an invisible, heavy gas. It chokes people effectively and quickly, and if you can be bothered to set the alarms up, will result in a invisible room that kills those in it. Takes some setup and can be very, very annoying. Causes people to gasp at low levels. Can be found in Atmospherics in black canisters or through the CO2 farmer.
	N₂O	Nitrous Oxide, a.k.a. Sleeping Agent. A white-flecked gas. Makes you laugh at low doses and at higher ones puts you to sleep. If using this as a sleep gas mix do not forget to mix in at least 16 kPa of O2, or you will suffocate someone. This decomposes into Nitrogen and Oxygen at temperatures at or over 1400K, creating Nitrogen equal to the amount of N2O used, and half that amount in Oxygen. Can be found in Atmospherics in red canisters with a white stripe on them or through the N2O farmer.
	Plasma	Toxins. One of the two flammable gases on the station, plasma is purple and highly toxic. Heating this at 10000K with enough with Tritium present will cause Plasma fusion. Make sure to take care of the absurd amount of waste products in the form of carbon dioxide, pluoxium and water vapors! They also tend to be very hot which makes great fuel for a turbine or TEG. Can be found in canisters in toxins or engineering, and Atmospherics through the plasma farmer. Can also be produced by grinding solid plasma then spilling them on the floor.
	BZ	BZ gas is a potent hallucinogenic that also put slimes into stasis, degenerates changeling chemicals and suppresses their hivemind. As a side effect, affected people will take low brain damage. BZ is formed when N2O and Plasma are combined at low temperatures in an exothermic reaction. Stops forming above around 1000kPa. Forms fastest at higher pressures around 200-400kPa If mixed in a tank with oxygen, it can be used for internals, to encourage spiritual development. Breathing it also produces BZ Metabolites. Export price per mol: 4 credits
	Nitryl (NO₂)	Nitryl (formerly Brown Gas) speeds you up - pretty good until your body burns up from the extra tension in your muscles. The result of heating Oxygen and Nitrogen to approximately 22500K at a 1:1 ratio, with at least 5 moles of Pluoxium. Higher heat improves efficiency.
	Tritium	Radioactive, flammable gas that is used in plenty of chemical reactions. Created by heating loads of O2 with Plasma. Also, radiation collectors convert plasma into this. Tritium, though not naturally radioactive, releases radiation when it is burned. Might not want to put this into any engine unless you plan to set it on fire. 250 moles can be used as a catalyst for Plasma fusion. Tritium is created in fires that are highly oxygenated, or, in fires where oxygen takes up a vast majority of the gasses. For example, 90% oxygen and 10% plasma. Different ratios may be used, and sometimes different ratios will end up being better for the highest level of efficiency depending on space in the incinerator and temperature of the fire. Experiment! Important to remember is that tritium will likely be very hot, and if allowed to react with oxygen will burn up into water vapor. Keep this in mind when attempting to get sizeable amounts of it. Export price per mol: 5 credits
	Hyper-Noblium	Extremely inert, Hyper-Noblium stops other gases from reacting. (Specifically, it stops reactions when >5 moles) Can be created when Nitrogen is combined with Tritium at extremely high temperatures. BZ works as a catalyst. 2:1 Nitrogen to Tritium is about optimal here. Counter to the Nitryl reaction, BZ is not a requirement at all. But rather, it decreases how much the temperature / energy drops of your gas mix during the reaction. As such, BZ can often be entirely ignored. The minimum temperature for this reaction to occur is 5000000K (or 5 × 10^6 in scientific notation) Export price per mol: 1000 credits
	Stimulum	An experimental gas that makes you stun and sleep immune and slightly regenerates stamina, but also causes suffocation the longer you've been breathing it (current cycle x 0.05 oxygen damage). Formed by combining Tritium with Plasma, BZ and Nitryl, then heating it. Also formed in high quantities by fusion. Export price per mol: 100 credits
	Pluoxium	A non-reactive Oxygen substitute that delivers eight times as much O2 to the bloodstream, with as little 3 kPa minimum pressure required for internals! Formed by irradiating tiles with 2 part CO2 1 part O2 in the air. The Supermatter can be used to naturally generate a small amount of pluoxium if CO2 is added to the cooling loop, but this is risky. A common byproduct of fusion, be sure to scrub them out! Export price per mol: 5 credits

Atmospherics Layout

A wise Atmos Tech once said: "just stare at the pipes until you get it."	"Simplified" picture of the Atmospherics pipe system. Yellow circles represent filters and the lightbrown circle represents the mixer.

Here are two pictures of the atmospheric pipe system. Right one is a "simplified" version of the left picture. Yellow circles representing the filters which filter out a certain gas from the Waste In -gasmix. The light yellow circle near the lower middle represents the mixer which mixes N2 and O2 into a breathable air mix.

Atmospherics is pretty simple, but the pipe layout makes it slightly confusing for the untrained eye. There are 4 major pipe "loops":

The dark blue pipe loop is the distribution loop. It sends air to all the vents on the station for the crew to breathe.

The cyan air mix pipe loop, which is specialized to mix and provide the air mix to the distribution loop, and is used to fill air pumps outside the front door of Atmospherics.

The red/green pipe loop, which retrieves the gas in the station via the air scrubbers (red loop) and passes them through a set of filters (green loop).

The yellow pipe loop, internal to Atmospherics, which is used for custom gas mixes that can be fed into the canister charging station in the middle of atmospherics, or fed into the mixing tank.

The tanks (the small rooms in space just outside of Atmos) of the station's atmospherics network, unlike in the rest of the station, are rooms filled with very high pressure of the appropriate gas. The output of these rooms are controlled by their respective Supply Control Computer, an on/off valve, and an output pump for each loop. Note that these rooms can be depleted, especially if someone makes a hole in a tank's external wall.

To understand how the breatheable air mix is mixed, try following these steps and looking at the map at the same time, it starts on the south end of Atmospherics, like so:

The gasses are pumped through the cyan tubes from their respective tanks (N2, O2).
They are mixed in the air tank (Air) to a 1/5 mix of O2 and N2.
The breathable gas is then pumped through the cyan loop to the north of Atmospherics.
And finally it's pumped into the dark blue distro loop and out to the station for everyone to breathe.

Next let's make up an example situation to see how the waste system works in action:

Scientist Bill messes up and fills the Toxins Lab with plasma but fortunately manages to evacuate the room safely.
Being an otherwise ideal situation Atmos-wise, the Toxins Lab's air scrubbers have been set to filter out all hazardous gases (they're not set by default, this has to be done through the Air Alarm manually or by asking the AI to do it) and plasma starts to get sucked through the scrubber into the waste pipes.
The plasma arrives to the Waste In -loop (the red pipe loop) at Atmos. It travels south through the pipes, its first stop being the N2 Filter.
If there was any Nitrogen in the waste gas, it would get filtered out here, and the rest of the gas continues its journey through the waste loop, same thing happening at every filter.
The plasma finally reaches the Plasma Filter.
Here the plasma gets extracted from the waste gas and pushed into the big plasma tank-room outside the windows.
The plasma stays in the room until someone decides to pump it out.
Scientist Bill by now notices that the Toxins Lab has no plasma anymore and is able to safely continue his work. Yay!

Setting Up Atmospherics

It's about time we stop with the theory ~~and throw it out the window~~ and get down to business. The two machines at the top can dispense infinite pipes, and your wrench can disconnect and connect pipes to each other. Remember, you cannot disconnect pumps if they have too much pressure in them.

The dumbass-version of the Atmospheric pipe system. See the steps what each colored circle means.

Next up is a very simple step by step guide how to set up the Atmospherics pipe system to be (nearly) as efficient as possible. Note that this is only one style how to set up the pipes, there are many ways and they all have their own pros and cons!

For the love of Nanotrasen, at least do this:

Get a Volume Pump from the Pipe Dispenser at the north side of Atmos and replace the green circled normal pump with a volume pump, making the waste gas -system >100x more efficient. We want the waste gas sucked from the station into the waste system as soon as possible!
Set all red circled filters ON and set them to maximum pressure (4500 kPa) so waste gases will actually be moved.

This is good as well:

Go through the N2 and O2 (besides southern wall) and set their output to 4500 kPa.
Set the pumps next to the computers at 4500 kPa also, so the gases being pushed out of the gas-room get moved fast too.
Set the Air-computer's output to maximum (5066.25 kPa).
Replace the blue circled normal pump with a Volume Pump as well, but notice; there are risks involved and all of them are covered at the pros and cons -section below.

Pros and cons of this whole setup:

+ Quick toxin filtering: In case of a toxin leak, waste gas will be sucked out quickly (if the area's air alarms are set to filter out all the toxins, that is, by default they are NOT filtering anything).

+ Quick repressurization: In case of a breach, air will be poured out with a nice pace, helping you re-pressurize the room quicker after the breach is fixed.

+ Reduced pipe sabotaging: With this setup, its harder for the grifflords to fuck up pipes in the maintenance tunnels. In a room with the default 101.3 kPa atmospheric pressure, pipes with more than 202.6 kPa pressure fling the unwrencher back.

- Air Alarm sabotages: The station is more vulnerable for sabotage through air alarms. Someone can quite easily hack an air alarm somewhere and set the vents to push out air at maximum pressure, resulting in overpressurization.

- Space wind: In case of a breach, until the hole is fixed, you'll probably spend a small while fighting against the huge air current, a.k.a. "space wind", if you don't switch the vents off during the repair. This is mostly just annoying.

- Very slow pipe manipulating: If you suddenly have to modify any of the distribution pipes around the station, you need to lower the pressure to under 202.6 kPa or use magboots if you don't want to be flung around like a leaf in the space wind, which can take a long time.

A little safer, but not as efficient, way of setting up the system is leaving the blue circled normal pumps completely alone or maybe raising the pressure to 315 kPa. This pressure is enough for quick pipe manipulating and for a sufficient air distribution.

Done correctly, Atmosia should be pumping good air just faster than it's lost, and draining bad air away as fast as the traitors can set it on fire or alternatively draining good air away as fast as a malf AI can siphon it. You can go kick back in the bar like a boss and wait for the inevitable minor station damage and cries of "Call the shuttle!" on the radio from folks who don't even know it ain't a big deal.

After the Work is Done

There is a short list of things which fall under your stead:

First and by far most important: make sure pipes don't get broken and if they do, fix them.
Go around swiping your ID on Air Alarms, setting the operating mode to contaminated, and then re-swiping to lock it. You can ask the AI to do this as well, and probably should.
Fill all the air pumps with air using a volume pump (more air pumps can be found from the locker room).
Make extremely extended oxygen tanks for internals use (instructions below).

Least importantly, maintain the disposals system. You can generate pipes, but it needs welding and is generally a pain in the ass. You can also make fun slides, though.

Optimizing Internals

On a basic view, a 16 kPa minimum O2 requirement in internals. Pure O2 is theoretically toxic in real life, but has no representation for this in code, and takes a while to be really dangerous anyway (they use it to treat certain diseases, for example), and thus using a tank filled with air for internals is fairly inefficient.
Cold O2 has more moles per kPa, and because people breathe in moles, and filling tanks usefully for internals are largely capped by the 1000 kPa release pressure, means cooling your O2 before using it in internals is important! Cooled down O2, such as from a freezer-ed canister, is the most efficient way to set up internals. Cooling it below 264 K will result in icicles inside in your lungs, though!
If you need to empty an internal tank to make space for better, colder O2, you can use an Air Pump. Set it to "pump in" and "turn on" then "off" with the tank inside it, making it completely empty, thus allowing you to refill the tank more effectively.
An emergency oxygen tank with normal settings lasts for about 12 minutes. Same tank, but with optimized gas temperature and output settings reduced, lasts about 50 minutes. If you don't have resources to get cooled O2 right now, set your output pressure to 16 kPa, it will give you 31 % more time to breathe.

Your Very Own Customized Mix

To create a custom mix of gas, turn on the output of the supply control computers, open the manual valves, and turn the output of the pump to what you wish it to be. The gas will travel through the orange pipes into the mixing chamber. The gas mix is pumped into the mixing chamber via a pump north of the orange loop.

The mix obtained can then be pumped into the distribution and filtering loop or used to fill canisters. Remember to turn off the pump between the yellow and red pipe network or your custom mix will just go into the red waste loop.

Fun Projects

The Atmospherics system is far from optimal, and we're talking about just the pipe configuration! Break out that wrench and start experimenting (just make sure you know what's what)!
Extremely high-temperature gases (like those from a panic siphoned fire) can really clog the waste loop. Could you do something to correct that? Tip: triple volume pump really helps.
No one uses the ports outside of the 'refilling' station, but that doesn't mean that functionality can't be added onto them!
On rounds with skeleton crew, you will have all the access of a station engineer. Go help fix and build the station.
Don't count out the grated window areas, they can be a great (har har) way to utilize the vacuum of space without an EVA suit.
Speaking of EVA suits, your engineering buddies can potentially help you with anything you might want to do in space, be it adding or modifying pipes.
The brigs distribution system is set up to be potentially independent of the rest of the station's distribution loop, maybe other places can be set up like this as well?
The AI sat air distribution is normally cut off from the rest of the station, straight pipe it and laugh as the AI accidentally burns down its own satellite.
The mining station doesn't have air recycling. Very long rounds might make this a problem for any miners working there. The easy way is just simply built a scrubber that only takes in oxygen and nitrogen and connect it into the mining distro. Alternatively pull Mr fastmosky into one of the rooms and set it to panic siphon, bots have unlimited supply of O2 and N2.
The supermatter on regular operation constantly releases oxygen or plasma, pipe them back into the distro, set up a TEG burn chamber or even do fusion (see below)!.

The Less Well Known Hazards of Gases

Any gas at pressure over 1000 kPa will cause you to start suffocating as in a vacuum. You can just use internals, though.
N2O is invisible at low pressures. If you start giggling, put on your internals to avoid passing out.
Any gas can displace O2, and less than 16 (also useful for optimizing internals) kPa of oxygen starts the Oxyloss. CO2 can be removed with the scrubbers, but to get rid of N2 simply apply some way of removing gas from the air and adding O2. My personal favorite is 2 air pumps, 3 connectors and an Air Filter and a canister: 1 pump draws in, goes through the connection and filters N2 into the canister, and the rest to the other pump, which expels it. Can also be used for N2O which is only sluggishly scrubbed otherwise.
Pressures above 750 kPa do 10 DPS + 5 DPS for every extra 375 kPa above that mark, rounded off. Space suits completely block it all, but there is no other defense.

ATMOS Resin

The Backpack Firefighter Tank can switch modes to launch transparent ATMOS resin instead of extinguisher. This resin has the following effects:

Repairs hull breaches similarly to Metal Foam.
Cleans the air from toxins.
Normalises air temperature to room temperature (20°C or 293.15K).
Removes slipperiness from floors (from water etc).
The foam itself is not slippery.

To use the Backpack Firefighter Tank, equip it on your backpack slot and click the new hud icon to take out the nozzle . You can then cycle modes between extinguisher, resin launcher and single tile resin launcher (foamer) by activating the nozzle in your hand. It spends water when used. Examine the nozzle to see water remaining. This anti-breach and firefighting tool can be ordered from cargo or found in atmospheric lockers.

Useful Atmos Trivia

Your holobarriers let people walk through, yet block gases. Very useful for cleaning up Plasma spills, fixing hull breaches and keeping fires in check.
Using H/E pipes in space you can cool things down to a very low temperature very quickly. By making a cross with two off them you can have two on one tile, which is known as 'sequesteral' cooling.
Air Filters on currently burning mixes can siphon out heated but PURE O2 and Plasma. Do the O2 first then the plasma, as there is less O2 in a fire and thus it functions faster. This (and H/E) allow you to reach really obscene temperatures.
Air Filters and H/E allow you to expose gases to the heat of fires (or their CO2 product) but keep/make them pure, allowing for hot N2O or similar.
Using a small starter flame/heater you can have in pipe combustion.
Canister bombs are heated Plasma in a canister, with an O2 tank placed in the canister, and then open the valve between them. You will also need to run very, very fast.
Gas pumps are for precise pressure control, volumetric pumps are for really fast pumping, and passive gates are for having 'one way' manual valves.
Passive vents in space vents air out faster than a 400L/s air injector. Good for dealing with excessive waste gases such as from fusion.

Fusion

So you want to operate a fusion reactor? Well, it's about as dangerous as it sounds. On various /tg/station-based codebases, fusion has been redesigned several times and is currently on version 6: "Chaos Hyper-Torus Edition". Each server has its own variation, but its divergence from original code is generally correlated with how often people do fusion, especially for griefing. So, for each codebase, you need to learn its finer details of fusion. But, first things first, let's see the most basic fundamentals of fusion V6:

Mixing at least 250 moles of CO2 (hydrogen on /tg/), at least 250 moles of plasma and at least one mole of tritium, and then heating it to >10000K satisfies the bare minimum. You don't have to follow this order if you are using air injector to an open turf. (e.g. Plasma and CO2 superheated to 50000K and then tritium works)
Depending on codebase, said "bare minimum" will die pathetically or not very badly. In order to continue the fusion, you need more tritium, more heat, and more plasma. More plasma and more heat is mostly here for a better luck.
Tritium is always consumed, one mole per reaction, so you will need a lot of them. The problem here is you can't pump in more gas to a fusing canister. In order to mitigate that, long-living canister fusion requires a lot of initial tritium. You also are unlikely to be able to add more tritium when the canister it in heating process, so you should take care of that too.
Fusion itself is chaos. The original author dubbed it using cool mathematical words, but that doesn't mean much. As energy fluctuates between plasma and thermal energy (E=MC² is kinda in work here), more initial plasma and heat provide a buffer against chaotic nature of fusion; chaos sometimes knocks fusion mix out of 10000K requirement. However, the chaos is ultimately on your side, so you will be able to get ridiculously high temperatures.
As the fusion goes on, the mix will create various waste gases. The resulting waste gas mixture will depend on codebase, but extracting them will be a hassle, and the amount won't be that much in the first place. The standard practice here is using fusion as a heat source.
Finally, the fusion creates radiation and perhaps a nuclear particle. (aka radball) Strength does depend on codebase, but the rule of thumb is that the rad here is deadly.

We can stop here. See, things sound good here. A great heat source! Atmos can do quite a lot of weird stuffs with this. But, enter the griefers. The greatest problem here was the heat. I said "ridiculously high" temperature, but, the thing is, the temp easily reached 1e+31. Nearly everyone involved in fusion wrongly assumed 1e+31K is a natural part of a fusion (and stopped using their brains like the rest of greater /tg/station fanbase) when the actual culprit here is an exponential increase in thermal energy caused by a bug.

So, servers had to (or will be expected to) deal with the eventual rise of 1e+31 griefers since no one (except the griefers) considered this as a reasonable situation. Whilst things like fusion griefing can be dealt with proper administration, some coders became brave and touched the cursed fusion V6 code.

Therefore, we now arrive at the Beestation's solution. You can take a look at it to get a deeper understanding of the current state of the art, which will inevitably be revised as griefers again somehow discover ways to heavily grief with it, but for the sake of accessibility, here is a quick and practical guide to the Bee's current fusion V6.

TL; DR: Do open turf fusion and supply plasma to it, and canister fusion won't get you far.

The Bee's current fusion V6, which has even more math than the original fusion V6, requires constant supply of plasma to reach higher temperatures. Without constant supply of plasma, the temperature is very unlikely to exceed 1e+7K, and sudden death becomes a possibility. So, to create a fusion that lasts and has higher temperatures, you need to practice open turf fusion supplied with an air injector. There is quite a lot of leeway here since numbers are a bit relaxed at the initial stages of fusion. Generally you will need 500~600 moles of plasma per tile heated to 20000K, preferably using heat pipes transfering heat from tritium production chamber.

The best practice here is having a constant supply of tritium and plasma and then injecting fresh tritium and plasma with an air injector. As the radiation scaling and nuclear particles provide nice indicators of the strength of a fusion, you will discover that the fusion respond quite well, albeit clumsily, to changes in plasma input; the resulting temperature eqilibrium depends on plasma input. If you can't see enough change, check your plasma supply. Supply more plasma for a better outcome. As the growth still is (marginally) exponential, high temperatures can be reached with ease, as long as you can supply enough plasma for them. In contrast, you can't supply anything to canister fusion, so the fusion canister will create meager rads and stay at <1e+7K. However, opening it still is highly dangerous, probably as dangerous as opening a heated can full of tritium.

Let's wrap up. There still are lots of details to say, but we will stop here with a final detail: it may sound surprising, the fusion still is uncapped (or capped to 1e31 which is essentially the same as not having a cap.) You indeed are extremely unlikely to reach 1e31 with current fusion unless you acquire billions of moles of supercooled plasma, but the math is forgiving (subject to change) and open. Experiment!

Fusion is DANGEROUS if high pressure fusion leaks it can FLOOD THE ENTIRE STATION WITHIN MOMENTS AND KILL EVERYONE ON IT

Being a Traitorous Scum

Or: How to get the AI lynched; How to call the shuttle as Atmos Tech, step-by-step:

Open valves connected to harmful gas you want to add to the station.
Set pumps to the distribution loop to maximum pressure output (4500 kPa).
Set filters to not filter harmful gasses you want to add to the station OR set the waste-in pump to 0 kPa (but leave it on to confuse the crew).
Open valve from custom mix chamber.
Turn on pump leading to distribution loop.
Wait for vents to slowly kick out your deathgas mix as regular atmos drains out through the inevitable hull breaches (alternatively turn off pressure checks on air alarms' vents to speed things up).
If you need to kill someone for your objective, and you want to be more proactive, the Fire Axe mounted in the wall is surprisingly effective. Just don't leave it lying around, because it's one of only two on the station.

To hurry this process up, you can set the air vents at local control panels to maximum output pressure. Not doing so gives the AI and Atmos Techs more time to notice what you've done and shut it off before it takes effect.

A faster process for achieving the same result is to do the following:

Disconnect, change the direction of, and reconnect the pump that feeds from the air mix to the mix tank in the north-eastern room of atmosia.
Open the valves for your deathgas mixture of choice.
Power on and max the pressure on every pump in the mix pipes (yellow pipes) from the storage tanks out to the station output (blue pipes).

This simply means that instead of the air mix being put into the mix tank as it normally does, the air mix (which may or may not contain death gasses) is fed into the station output.

Crafty atmos traitors will want to cut cameras, replace pumps with pipes, use tricky pipe configurations to avoid the AI interfering or the detective trying to fix it and make a hole in the station's oxygen and air tanks, venting the entire round's supply of oxygen into space.

An extremely fast method that involves a clever use of the waste system is the following:

Reconfigure the piping to connect the waste system directly into the pure pipes.
Find a place with a waste pipe next to a distro pipe, then configure them so that they can be united later.
Open the valves for your deathgas mixture of choice, the waste piping should now begin to fill with your gases.
Set as many air alarms as you can to have every vent at Internal 0.
When ready, go back to your distro/waste pipe spot and unite them.
Listen to screams over the radio. Or break tcomms so their calls for help never reaches medical's ears.

Other antagonistic things to do:

You can hack an air alarm to use it as a non-Atmos Tech.
You can C4 the digital valves to let you remove them and shut down AI control, or save a C4 and disable the cameras if you know there are no Cyborgs on the station.
Using a gas filter turned on to pour large, ever increasing, amounts of gas onto a single connector port has no visible effects, but if you wrench a canister onto it then the canister will almost immediately fill up with the massive pressure buildup, letting you get super-high pressure plasma/CO2/etc canisters to hit area's with.
Doing fusion? Pipe the extremely hot air into distro and watch everyone even with firesuits scream at a billion degrees when the usual plasmafire protection doesn't work. Get instantly banned if you don't have the right traitor objective.
You have access to a circuit imprinter in engineering, go subvert the AI and let it do all the above for you!
If your objective involves stealing the blackbox. You're in luck because you have free access to it on some maps.
Have access to the Supermatter? Turn off the scrubbers, prevent the SM doors opening by putting a holobarrier or wall. Now feed it with Nitrogen to cause it to become a singularity or CO2 to cause it to become a Tesla. Or all the gases if you want to do both.