Andy did not have the right machinery to construct a second door to form a real airlock. Instead, he would be relying on attaching and detaching an iron sheet from the open wall frame to fill the roll of a second door for the time being.

That being said, the principle by which this airlock would go about working is that there are two separate active vents and pipes. One active vent and it’s pipe would be dedicated to the external atmosphere and the other active vent and pipe would be dedicated to the room's atmosphere.

Andy ‘borrowed’ the fuel canister from the generator and put it back in his blow torch, sealing the open wall frame with an iron sheet. He then returned the fuel back to the generator and turned it on.

With the ‘airlock’ now sealed, he set the ‘external’ active vent to suck in gas and turned it on. After about half a minute, it had sucked up all the available atmosphere in the ‘airlock’ and held it in it’s private pipe. The ‘external’ vents pipe now contained atmospheric gases and the ‘airlock’ was in a vacuum state.

Now he opened the bedroom door. He braced himself for the dangerous flow of pressure from the 102kpa room to the 0kpa ‘airlock’. Mass depressurisation like this was always dangerous as it could cause objects and you to fly around at high speed.

Andy was pressed up against the wall, hard, until the pressure normalized. Luckily nothing too dangerous flew at him and only some furniture shifted around a bit.

This was the last time he would have to do that. Now he could use the airlock normally.

Exiting involved first closing the ‘internal’ (bedroom) door. Then setting the ‘internal’ active vent to suck up gas and turning it on until the airlock was in a vacuum state. Then turning that active vent off.

Next he would set the ‘external’ active vent to pump out gas and turn it on until it pumped the full contents of its pipe back into the ‘airlock’. Then he would turn that active vent off as well and could now open the ‘external door’. As in, remove the sheet from the wall frame with his crowbar.

And that was the process of exiting the bedroom via the ‘airlock’. Entering was simply the reverse of that process. Each vent and attached pipe was responsible for holding and transferring a different set of atmosphere (the planet's atmosphere and the room's atmosphere).

The reason he didn’t just save some resources and use one set of active vent and pipe, for only the room’s more desirable atmosphere, is because he would be forced to open the vacuumed out airlock to full external atmosphere pressure every time he opened the wall and as stated before, any kind of mass depressurisation was dangerous.

There were still some minor issues, like if he went into the room while the external atmospheric pressure was 150kpa and the airlocks gas at that pressure got stored in the pipe, if he exited when the external pressure was higher (say during the middle of the day), then pumping that gas back into the block would still only result in an airlock with 150kpa gas pressure, lower than the outside. You’d still have a risky air flow when opening the airlock.

Not that Andy planned to go out during the day ever again, but you could never be too careful.

He had also needed to use insulated pipes for this and not regular pipes, because if he went outside and stored some of the bedrooms atmosphere in the ‘internal’ pipe, it would, no matter how he shaped it, be exposed to some of the external atmosphere and that would affect the temperature of the ‘bedroom atmosphere’ stored in the pipe. An undesirable outcome to say the least.

Andy then ‘borrowed’ some more wire and connected the cable from the generator's new home inside the airlock, over to his existing ‘manufacturing’ power network. The generator would have to remain in the airlock for now as he needed his one and only fuel canister to power both the generator and his blowtorch while operating the ‘airlock’.

Now that he had a way of maintaining the bedroom's atmosphere, he needed to go back to solving his original problem... cooling.

First Andy conducted a quick test. While the high pressure gas was still inside side B of his cooling loop, he disassembled one of the high pressure pipe segments. Nothing happened. Inspecting the remaining pipe segments with the PDA’s atmospherics function, he noticed that the pressure had gone up.

This meant two things. First is that any gas in the pipe he is removing, is automatically forced into its neighbouring segments. Second is that the open ends of the remaining pipe are automatically blocked off by the game. A convenience feature that was clearly added to allow players to more easily work on their bases and systems.

Andy put the missing pipe segment back and attached a vent to it to let the excess high pressure gas vent back into the atmosphere.

Once that was done, using a combination of his wrench and hand drill, he proceeded to disassemble his little cooling experiment. He then moved all the parts over to the airlock and sealed it behind him. He repeated the lengthy process of entering the bedroom.

Once inside, he got to work.

He attached just under half the pipe on the inside of the bedroom wall, next to the window. He put the pump on one end, and bent a pipe through the wall from it. He would later go outside and hook up something to the other end. He then put the valve on the other end of the internal pipe and once more bent a pipe from it to the outside. Lastly, he created a T-junction in the middle of the inside pipe (basically once more side A), and bent it outside.

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Now Andy exited the bedroom via the airlock and it’s lengthy exit procedure.

Once outside, he went around the outside of the base to where the external side of the bedroom window was located. Here he could see the three pipe points sticking through the wall. Andy closed the loop between the pump and the valve's pipe ends. He also added a vent to the piece of pipe leading to the T-junction.

With this complete, he was ready. He went back to the airlock and made his way into the bedroom once more. Inside, he connected the power cable up to the pump. He set it to ‘high’ and turned it on.

The cooling loop now sucked up atmosphere via the external vent and built it up in the external pipe. Andy used the PDA to keep an eye on the pressure of the external pipe. He did this by pointing the PDA at the small bit of the external pipe that was actually sticking out inside the bedroom, in front of the valve and the pump.

Once the pressure reached 20mpa, he ‘cut out’ the single segment of pipe leading from the T-junction to the external vent, effectively cutting off the supply of atmosphere. Once the remaining gas had been sucked up into the external pipe, he repeated the procedure from his earlier experiment.

Turn off the pump. Set the valve to match the pump's flow rate. Wait a little for some gas to fill the inside pipe. Turn the pump back on. And voila!

Over time, the cooling loop would cool the atmosphere in the bedroom via the ‘cool’ side of the pipe present, and transfer the heat out via the external side of the pipe with the high pressure.

Unfortunately, he wasn’t sure how long this process was going to take. Andy checked with the PDA. It was a bit alarming that the gas in the ‘inside’ pipe was initially higher than even the room's current temperature, but after a short while, it quickly corrected itself. Soon the gas in the ‘inside’ pipe became much lower than the room's temperature.

Perfect!

With this, it was only a matter of time. After a while, it would cool the room’s temperature back down to acceptable breathing levels.

The biggest problem was that he did not have that long left. His hud was already giving critical O2 pressure level warnings and he could feel that his suit’s oxygen was starting to thin out. The game also seemed to darken his vision ever so slightly now, no doubt their representation of him being oxygen deprived. It would likely get worse as things progressed. Andy sucked his breath in frustration. Not this shit again! He needed more time. But what could he do? The only oxygen around him was too hot. It was unbreathable. There was no way for him to rapidly cool oxygen down.

The only thing here that could cool stuff down was his new slow acting coolant system and his suit which did a bit of cooling using battery power. But it’s not like he could just swap his hundred and fifty odd degree waste tank with his O2 tank. Even though the waste tank no doubt contained a fair amount of oxygen, his suit wouldn’t be able to cool it fast enough for it not to fry him.

He could open his helmet and breathe the atmosphere in the room, but that would put him back in health drain mode due to the still present toxins and he still hadn’t recovered enough health to survive that for an extended period of time. Likely not long enough anyway.

He could try and scrap more iron to build a setup to purify the atmosphere in this room, but between the time to harvest sheets, scrap them, construct stuff, setup the rig and run it long enough to purify. There was no way he had that much time left. Least not going by the rate the darkening effect was progressing.

Fuck. Fuck. This is such bullshit. So Close! As Always! Ever since he had that bullshit start to the game, it’s just been one unreasonable uphill battle after another.

Maybe he should just give up and fucking die already. After all, the game wanted him dead really badly apparently. Maybe he should just let it kill him already.

Andy suddenly didn’t feel like doing anything anymore. He just wanted to throw off this damned space suit and curl up on the bed and die. He felt the familiar feelings clawing at him, dragging him down.

He’d been so busy trying to survive all this time, that he hadn’t even had the chance to feel depressed. That was the funny thing about depression, they say that one of the best ways to stave it off was to simply keep busy, have a routine and such. And they were right, that did work. Keeping busy usually meant he didn’t have time to sink into depression.

Problem was, it worked both ways. When you finally did get depressed, you didn’t feel like doing anything, you know the thing that would help distract yourself from the depression, literally anything!

Andy stood there, all life drained out of him. He watched as the darkness increased. As the coolant loop continued chugging along, lowering the temperature of the room, bit by bit. As the temperature in his waste tank started to decrease as well, from spending time in the ‘cooler’ room.

Wait! That was it!

The revelation was enough to more than sufficiently distract him from any depression.

Andy dived into his hud menus and found the settings for the waste tank. He then proceeded to open up the waste tank's internal suit valve a little bit. It was normally closed as the filter that absorbs the carbon dioxide and deposits it into the tank was a separate thing. There was after all no reason to dump potentially lethal CO2 content or mass heat from your waste tank back into your suit.

However, opening it up only slightly, meant that there would be a small and steady flow of really hot O2, with a sprinkle of CO2, into a suite that was filled with alot more cooled pure O2 than what was being injected from the waste tank. The result was that the temperature inside the suit would only rise slightly and the suit's powered cooling system could keep up with it.

As for the CO2 being injected back into the suit, the CO2 filter simply had to work double as hard to filter it all back into the CO2 tank again. Sure, part of that CO2 would come back into the suit again, in some kind of vicious cycle, but for now, the filter could keep up.

Eventually the CO2 build up would start overwhelming the filter and that would become toxic and this would use up both the filter and his suit’s battery faster, but Andy was confident that this would hold out long enough.

Unfortunately, he was stuck here for now, since he needed to cool the room, but more importantly, stay here so he could cool the waste tank via the room. Then finally he would have access to a fresh supply of Oxygen without any more crazy hacks.