Atmospherics

Atmospherics is a branch of engineering responsible for air on a station and producing new gases.

Gases

Main article: Gases

The bread and butter of the Atmospheric Technician. Gases can be found within:

1. The air around you, so long as there are four walls and a floor enclosing it and preventing it from escaping into space,
2. Containers like portable gas tanks and large gas canisters,
3. Pipes and other atmospheric devices, and
4. Your character's lungs (hopefully)

The standard station atmosphere is a mix of 21% oxygen and 79% nitrogen, at 101.3kPa and 293.15K (20°C).

Gases in SS14

Gas	Description	Specific Heat Capacity	Heat Capacity Ratio	Molar Mass (g/mol)	Spesos per mol when selling
Oxygen (O2)	A colorless, odorless, and reactive gas. Oxygen is breathable for most species aboard the station, but toxic for Vox to breathe. Enables flammable gasses to ignite and burn. Every station includes a gas miner for oxygen, as it is a primary component of the station's atmosphere. Canisters containing oxygen are painted blue, with a horizontal white stripe. It can also be found inside similarly colored gas tanks. Extended emergency oxygen tanks are painted yellow, instead.	20	1.4	32	0
Nitrogen (N2)	A colorless, odorless, and inert gas. Breathable by Slimes and Vox. Every station includes a gas miner for oxygen, as it makes up the bulk of a station's atmosphere. Canisters containing nitrogen are painted solid red. Nitrogen gas tanks may also include a white stripe.	30	1.4	28	0
Carbon Dioxide (CO2)	A colorless, odorless, relatively inert gas. Exhaled by creatures that breathe oxygen. Toxic in high enough quantities. The reason why atmospheric technicians are employed. Some stations include carbon dioxide gas miners. Canisters containing carbon dioxide are painted solid black.	30	1.3	44	0
Template:EmbedVideo Gif Frame	A purple, putrid, highly-combustible, and toxic gas. Will combust when in the presence of oxygen and ignited. Vitally important to industrial and scientific activities aboard NanoTrasen stations, such as some chemical reactions or power generation. Formerly known as phoron. Canisters containing plasma are painted solid red-orange, with a white "P" near the bottom. It can also be found inside orange plasma gas tanks, dispensable from Engineering's gas tank dispensers.	20	1.7	120	0
Template:EmbedVideo Gif Frame	A green, highly-combustible, and radioactive gas. Will combust when in the presence of oxygen and ignited. Not mined or found on station at round-start, but can be produced through controlled burns of plasma. Canisters containing plasma can be painted neon green with black hazard stripes, but they are not found on stations at round-start.	10	1.3	6	2.5
Template:EmbedVideo Gif Frame	Water in gaseous form. Due to the unique environment of space, does not condense into liquid water. Causes heat damage to Slimes on contact. Some stations include a water vapor gas miners. Canisters containing water vapor are painted black, with pale red stripes.	40	1.33	18	0
Ammonia (NH3)	A faint purple, pungent-smelling gas. Breeds disease, and toxic in high enough concentrations. A byproduct of nasty biological processes, including rotting bodies. Formerly known as miasma. Canisters containing ammonia are painted light green, with yellow stripes.	20	1.4	44	0.15
Nitrous Oxide (N2O)	A colorless, odorless, inert gas. Otherwise known as "laughing" or "sleeping" gas, it acts as a sedative to non-Slimes and is toxic in very high concentrations. Exhaled by Slimes. Canisters containing nitrous oxide are painted red, with pale red stripes.	40	1.3	44	0.1
Frezon	A light blue, odorless refrigerant gas. Used as an industrial coolant and thermal-exchange gas. Used recreationally by some for its euphoric effects, before their lungs freeze out. Reacts with nitrogen to produce nitrous oxide and drastically cool the atmosphere. Not mined or found on station at round-start, but can be produced through controlled reactions of tritium, oxygen, and nitrogen. Though it is less valuable per mole than tritium, far more frezon can be produced from a given amount of tritium, and as such it is a highly valuable gas to sell for spesos. Canisters containing frezon are painted light blue, with white stripes.	600	1.33	50	1.0

Atmosia

Atmospherics, sometimes referred to as Atmosia, is where most of the station's air handling machinery is located. Each station has a different atmospherics layout. While seasoned atmospheric technicians may have atmospheric layouts memorized, frequent useless station remodeling station engineering changes mean that it is more important to be able to quickly understand the layout of the station that you're currently working on.

Atmos Annotated

A typical atmospherics layout is shown below:

1. Nitrogen holding chamber with (maybe) a nitrogen gas miner
2. Oxygen holding chamber with (maybe) a oxygen gas miner
3. Pump for moving nitrogen to the mixer
4. Pump for moving oxygen to the mixer
5. Mixer to mix nitrogen and oxygen in an appropriate ratio for the station
6. Volume pump to move mixer output to the station's main distro pipe
7. Main distro pipe
8. Valve to shut off freezer
9. Freezer to reduce air temperature in distro
10. Valve to shut off heater
11. Heater to increase air temperature in distro
12. Main waste pipe
13. Volume pump to move air into the filter banks
14. Bank of filters to separate different types of gases from the waste pipe

Holding Chambers

Gas holding chambers

Holding chambers store a supply of gas for you to pump into the station when needed. Some stations come with gas miners that produce an unlimited supply of the mined gas. Walls and windows prevent gas from escaping to space; if the holding chambers are broken, then the gas inside will be lost.

Holding chambers may be labeled with the type of gas that they are designed to store.

Use pumps to move gases in and out of holding chambers.

Distro

The station's main air distribution loop, also known as distro, supplies the air vents that pump air into the station. It is usually colored dark blue to make it easily identifiable.

Air vents will pump air from distro into the station as long as the pressure inside distro is positive. Increasing the pressure inside distro allows the air vent pumps to move air faster. Contrary to popular belief, the pressure inside does not set the pressure of air coming out of the actively pumped air vents that start connected to distro.

Check the pressure of distro at round start and periodically throughout the shift. Low or slowly rising distro pressure at round start is a sign of shoddy station quality design flaws causing low flow rates into distro. Low distro pressure in the middle of the round may be indicative of spacing on the station.

Setting Up Distro

Setting up distro means to configure the layout to more effectively pump gases into distro. Specific steps to do so vary from station to station. Here is an example of setting up distro for the example above:

1. Remove (6) and replace it with a straight pipe segment. Pumps reduce gas flow rate, and when spacing occurs, (6) is typically a bottleneck when re-pressurizing the station.
2. Set (5) to output 310 kPa. The pressure in the distro pipe influences how quickly air vents can move air from distro into the station. Setting this too low reduces the flow rate, but setting this too high could be dangerous if a Traitor replaces an air vent with a passive vent.
3. Increase output pressure of (3) and (4) to their maximum settings.

Waste

Waste, or the waste loop, is usually marked with red pipes and is responsible for removing waste gas around the station via scrubbers. These pipes start and end in atmospherics and are looped around the entire station. The main purpose of the waste loop is the ensure that harmful gases get removed from the station's atmosphere. Scrubbers will remove gas from the hallways and return it to Atmospherics where it will then be separated by gas filters into various holding chambers. Harmful gases will be deposited into their assigned chambers and the breathable air will once again make its way back to Distro and into the station to continue the cycle.

Mix Chamber

A mix chamber in use

The mix chamber is an empty holding area with its own separate loop of pipes and pumps in atmospherics. The mix loop is generally marked with brown pipes and the holding chamber can usually be found close to the external hull, separated from the station by reinforced walls and windows. There will be an emergency button nearby to vent the chamber to space if you need to dump your mix in case an accident arises, or you just wish to reset the chamber for a new mix. The mix chamber is here for you to experiment with different mixes, ratios, temperatures, and pressures while combining gases.

On most stations the Mix chamber will loop around to the TEG, or to a passive vent in space. It is generally bad practice to have your mix loop flow back into the waste loop to recycle any unspent gases. Doing so can cause severe temperature issues on the entire station. You should NEVER have the mix loop flow into distro or waste loops unless you have a very good reason. Most savvy Atmospherics Technicians physically disconnect the mix loop from distro at round start to prevent an easy sabotage target or accident from occurring later in the round.

See the guide to Gases if you are interested to learn how different gases interact with each other at different temperatures and pressures.

See the guide to Setting up the mix chamber if you want to learn how to properly and safely use the mix chamber.

Pipes and Machinery

Main article: Pipes and vents

Temperature, Pressure, and Mols

Gases expand to fill their container, or escape into the space around them when not in a container. All gases can be quantified by their pressures, quantities (in mols, pronounced "moles"), and temperature. Pressure is how tightly a gas is packed into a given volume, mols show how much gas there is in total, and temperature is how hot the gas is. Each of these variables are closely related, and directly affect one another -- this is known as the Ideal Gas Law.

• Increasing the volume of a given container (a room, gas canister, gas tank, or another containment device) will lower the temperature and pressure. A larger room or tank requires more gas to fill than a smaller one.
• Increasing the mols of gas in a container will increase the pressure. Adding more gas to a room or tank will make it more pressurized, and removing gas from it will decrease its pressure.
• Increasing the temperature of a gas will increase its pressure. Making a gas hotter makes it expand, pushing harder against the edges of its container, and cooling it will decrease its pressure.

Pressure is measured in kilopascals (kPa), quantity is measured in mols (mol), and temperature is measured in both Kelvin (K) and degrees Celsius (°C). To convert from degrees Celsius to Kelvin, add 273.15 to the number.

When dealing with multiple gases, they can be divided into the fraction of pressure that they contribute to the atmosphere, also known as their partial pressures. For example, the standard station atmosphere is a mix of 21% oxygen and 79% nitrogen, at 101.3kPa and 293.15K (20°C). This means that of the 101.3kPa atmosphere, there is about 21.3kPa from oxygen and 80.0kPa from nitrogen. This is particularly useful when manually setting an appropriate pressure for internals, as your character only needs to breathe 20 mol of oxygen or nitrogen (or 20kPa partial pressure of the standard atmosphere) to not gasp or take airloss damage. This is different from over/underpressure damage, which comes from the environment your character is in rather than breathing.

When your character gasps (while alive and not crit), it means you are not breathing enough oxygen or nitrogen. This happens at below 80% of the normal level, or 16 mols in a breath. Gasping will take longer to recover from when breathing below 20 mol per breath, and will not stop when at or below 16 mol per breath. Some species, such as Slimes, are resistant to airloss damage, but gasping damage will still occur at the same thresholds.

Barotrauma (pressure damage) occurs when the environment is over- or under-pressurized, and damage increases the more extreme the pressure is. Some species, such as Arachnids, are resistant to pressure damage, but it will still occur at the same threshold.

Burn damage (damage from extremely high or low temperature) occurs when the environment is too hot or cold for your character. These thresholds are different for different species. For example, Reptilians favor higher temperatures and can survive comfortably in hotter environments, but will take damage from meager lower temperatures that other species find livable.