Oxygen Not Included - Tutorial Bites - Gases 

A good point, and this is one of the few uses for chlorine - but even then it's not that useful!

Not specifically on pressure no, but you've really hit the nail on the head already there. The gases in ONI are a bit 'sticky' but they do separate into layers by density as I showed here. The oxygen diffusers will overpressure at 1.8kg which is perfect for dupes, and then you need to have enough airflow to let it get around the base. Making 2/3 tile wide ladder areas is perfect, and I usually add a few airflow tiles between each room to help too. Then once you can move onto a SPOM (Self-Powered Oxygen Machine), you can use the gas pipes and vents to distribute oxygen to 2kg/tile. The carbon dioxide still falls down to be dealt with. Definitely have a look at the Oxygen Tutorial Bite if you haven't seen that already.

@@GCFungus after I asked this question I went into sandbox mode and played with a few things. some things of note: 1) Gases don't up or down unless forced to. In a room full of O at 1kg each, if you put 1kg of Polluted O (same density as O) in the center of the room vertically, the PO won't go up or down, ever. It just keeps moving around horizontally. This is kinda annoying actually, because it's hard to control where the PO will go then since you can't just count on it "eventually moving up or down into a space". This means you want flat tunnels for moving CO2 around though since it won't really move up if the O pressure is not low. 2) There's a vertical height exploit for high pressure gases with different densities. Say you have a room that's 2 tiles tall, and however long you want wide. you can put 100kg of CO2 on the bottom and 10kg of O on the top layer. You would THINK that the insane pressure CO2 would compress the O tiles into fewer tiles...but instead nothing happens. The 100kg of CO2 stays on the bottom layer, held in place by the 10kg of O. If you increase the height of the room to anything greater than 2 tiles though, the CO2 is then able to behave less exploity. NOTE, this 2 tile V limit means you can use low pressure CO2 instead of water at an airlock to get a perfect seal; long as germs aren't your concern. Dupes don't get wet, all you need is just to keep the other tiles at a higher pressure. 3) The O Diffuser emits it's gas from the second tile up, and that was just a minor question I had. 4) I think I found a clue as to why you need wide tunnels to diffuse gas pressure, gases seem to have a significant limit on how much can flow from a high pressure tile to a low pressure tile. I put one tile of 100kg O in a 1 by 2 vacuum room, and hit pause the instant something happened. You would think, that 100kg in a tile would instantly fill the adjacent 0 pressure tile with 50kg within 1 tick. Making them 50kg in each...but instead, only 12kg went to the empty space on the first tick. on the next update, less than 12kg moved to the tile again. I think there might be something like a 12% cap on how much airflow tile A can send to tile B per tick, and that would certainly be a problem for narrow tunnels. 5) If you're curious, a tile of 100kg O dropped in a large vacuum seems to send 12kg in all 4 cardinal directions in one tick - with a strange quirk of also sending it to some, but not all, non-cardinal directions as well. So within one tick 100kg went to 22kg.

@@Layarion That's interesting, and I was aware of most of what you found already. The game does have a 1 material per tile limitation, so yes two gases won't swap places if there are only 2 spaces to do so - this is the principle many SPOMs work on by forcing the hydrogen through a 1 tile gap. There is a similar behaviour with liquids, where a couple of grams of a liquid can hold back many tonnes of another (or a gas) because it can't be displaced. Also, although PO2 doesn't move vertically, in real games it does tend to form layers because of this behaviour. Basically whatever source is producing PO2 will keep making it at the same height, which then moves horizontally. But yeah you need to put deodorizers at the right heights.

Placing a tile will displace the gas. If the same gas is in a tile next to it, they will merge increasing the pressure. If not then it will be deleted, which is a more common use for building tiles in this way. If you want some ideas for infinite storage, I have a tutorial bite about that: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-7DVryDEbdcY.html

Well the nat gas gen does do that somewhat.

@@GCFungusas in, a gas boiler that doesn't choke my base with CO2 and piss on the floor when it's running!

I covered some of the tools in the Sandbox & Debug Tutorial Bite, but to clear out the map either you want to use the sandbox delete tool or use the debug instant dig + mop command, and replace any gases.

I'm aware of this, and I don't think they've changed the gas model at any point. But I've never designed anything with horizontal gas movement in mind and not had any issues.

@@GCFungus thanks for the reply. Good to know

Liquid oxygen is an oxidizer that is used in rockets to be burnt with the fuel. In the base game it is required to unlock the furthest destinations of the starmap with the petroleum & hydrogen rockets. In the spaced out DLC it is never actually required (it is the equivalent of a large tank of oxylite) but gives you more usable height for the other modules. I am planning to have a tutorial bite on liquid oxygen & hydrogen out in the near future.

@@GCFungus Thank you for the informative reply! Looking forward to the tutorial bite, cheers