The Caveman SPOM

[Yobbo]

It is a common misconception that cavemen are stupid. This is untrue. If you had to live in a cave, would you survive? You might! Because you are smart, like a caveman. Or like a cave-woman. The point is that living with complex things is easy, but living with basic things is hard. And so i present to you the Caveman SPOM. It converts water into oxygen. It needs no external power. It requires no refined metals, no fancy gold amalgam, and minimal research. It will give you oxygen before you finish building it. You can mess it up as much as you like, and just keep rebuilding it until it works. And once it's up and running it will keep running just doing its job and giving you oxygen. You can even open it up and tinker with it and it will keep doing that while you work. You can stop using the oxygen, and it will stop making the oxygen. Then when you start using it again, it will start making it again.

It is not the fanciest of designs. If you want something fancy, go search for "Hydra", or "Rodriguez". But you can build it at the start of the game and it will give you oxygen. Job done. And if you are concerned about efficiency, it is 99.5% oxygen-efficient, and can run at up to 98% of theoretical maximum capacity. That's up to 865g/s of fresh O₂, enough for 8.65 duplicants. Hydrogen is wasted. But that is perfectly fine, because you can neither breathe nor eat hydrogen.

The plumbing could not really be much more simple.

The wiring also.

The ventilation however is complex, which is why caveman must be smart.

It's not all that complex though. It's just a mechanical / valve filter for the hydrogen, bridged onto by two separate gas lines, which then join into one oxygen output line. The hydrogen output has an overflow, which it will almost never need.

Later when you have fancy smart batteries and automation, you can replace the dumb battery and tap the hydrogen overflow. About 5% of the produced Hydrogen is wasted by the design, which ends up reducing excess to around 85% of its theoretical maximum. Which is pretty much the same as a poorly-constructed Rodriguez. Or one where you just didn't set one of the atmo sensors to the precisely correct arcane value.

If the pumps and electrolyzer are constructed with gold amalgam, then it can accept a higher temperature of input water. Using another metal such as copper ore, it requires relatively cold water (under 60°C) to be fed in. The water will cool the machinery. If the machinery is made of gold amalgam, then it can handle input water up to 95°C or higher. The output oxygen will be hot, but it will work.

 

Now if you know what a valve filter a.k.a. mechanical filter is, there's probably not much more to say about this build. But maybe you don't, so i'll describe exactly how to construct it. If you already know how to construct this from looking at the above images, there's no need to read the rest of this post.

Step 0: Research

Spoiler

Research needed is straightforward. You need electrolyzers. They make the oxygen.

To power itself it needs a hydrogen generator. This will take advanced research, so you'll technically need that too before you can get the hydrogen generator part.

You will eventually want insulation.

Everything else is provided in the techs leading up to these.

Step 1: Build the electrolyzer

Spoiler

Dig (or build) the space to use. Place down a hamster wheel, battery, and electrolyzer.

The pipes are snakey to provide cooling for the pumps and electrolyzer. That's all.

Everything here has been spaced to make room for the final layout.

At this point, the system will already produce oxygen. It is a good idea to have a pocket to collect hydrogen where the pumps will go, like is done here.

Step 2: Prime the filter

Spoiler

The finnicky part of the build is priming the filter. It needs to be filled with hydrogen before use or it will not work. This can be done fairly simply just by building the ventilation system in a certain order. First place the pumps and gas valve.

The gas valve must be set to 0.1g/s. This can be done by typing the value in to the text box. The hamster wheel should be set to 0%, so it won't be used unless the system is starting up, or has completely broken down.

The pumps can be turned on at any point. They will pump mixed gas towards the bridge in the top right, and everything will then block.

Deconstruct some pipe sections to isolate one or two segments of pure hydrogen.

This hydrogen can be inserted into the valve filter loop using a bridge. Make sure to set the filter to 0.1g/s. It will then start looping tiny 100mg packets as can be seen here.

At this point the filter is primed, and everything else can be done in any order.

Step 3: Hook it all up

Spoiler

It's best to build the hydrogen generator next so hydrogen doesn't go everywhere. The bridge allows for overflow only when the pipe is full.

Reconnect the rest of the pipes and bridge both pump lines on to the filter. The bridge here was already in the right place, but i removed it for clarity.

Now connect the output line to a vent so pumped oxygen can start flowing.

Let it run a bit to clear itself, and voilà. It now works. Oxygen comes out the top, hydrogen gets devoured at the bottom.

This will work fine as-is, but if you run it at full capacity it's possible the hydrogen generator might struggle to burn all of the hydrogen. I usually add a small overflow vent so at least i know where the hydrogen will go in that case.

Now the oxygen is ready to be piped anywhere.

It will easily provide enough to aspirate 8 dupes, so long as the input water keeps flowing. If you have less than 8 dupes, it will simply use less water.

Step 4: Insulate

Spoiler

Depending on water temperature, this may not always be necessary. But you might as well do it, and not find later on that you've cooked your crops and everybody is going to die. Best to insulate the electrolyzer box, and make it a contained problem.

Tidy everything up.

And done!

Done

Spoiler

With oxygen a solved problem, even a very early base can be pretty much entirely self-contained. Just add decently cool water, and it will run forever. This one was easily completed by cycle 25, and already containing almost all the infrastructure needed to keep a small group of dupes alive indefinitely.

 

[Gurgel]

On a somewhat related note, I just verified that my anti-SPOM design ("doing it for the Hydrogen") still works nicely: 

 

[LadenSwallow]

I run a remarkably similar setup, but I extend the hydrogen filter loop to allow more bridges onto the filter, which you can extend into other 'modules' if building multiple SPOMs. I think I previously arranged my gas pumps vertically, but I am considering horizontal with a vertical offset of 1 so the + extraction areas of the pumps hit 10 of the 16 cells.

[Yobbo]

Yeah, i've been using this type of thing in various configurations as well for a long time. I'm a bit surprised it's not more common.

I did test several configurations of the pumps and electrolyzer. Previously i was always offsetting the right-hand pump down by one, so the extraction areas match up perfectly. But i found it doesn't actually matter much - the most important thing is sitting one of the pumps directly on top of the electrolyzer so it can pump directly from the output tile. The placement of the other pump had only minimal effect.

I also tried blocking some of the non-pump tiles so there was almost nothing that wasn't reached by the extraction area of one pump or the other. But it actually made the hydrogen efficiency slightly worse - i guess the back-pressure from blocking off space the gas could otherwise expand to leads to more situations where a packet of hydrogen can't move away quickly enough and gets deleted.