Doomsday Bunker Upgrade Chapter 27: 1st upgrade

　　 "Ahem!" Chen Xin was awake.

Today is the third day that Chen Xin has entered the shelter. After two days of adaptation and adjustment, Chen Xin feels that he has adapted to the life in the shelter.

It's just that today, for some unknown reason, the entire shelter was filled with the choking smell of smoke, which made Chen Xin wake up directly from his sleep.

　　 coughing and covering his mouth and nose, Chen Xin got up from the bed and turned on the light in the room.

　　 He tremblingly put on his clothes, but he still felt dizzy, and even his breathing was not smooth.

Chen Xin knew that this was not because he had not yet woken up, but because the choking smell of smoke in the air contained harmful gases. He inhaled a lot of smoke in his sleep, which affected his breathing.

　　If he was not woken up and continued to sleep like this, it is most likely that he died from lack of oxygen or poisoned gases in his sleep.

Chen Xin, who had reacted, hurriedly found a gas mask and an oxygen bottle from the cabinet beside him. After taking a few breaths of oxygen, he put on the gas mask.

　　 took a few breaths of oxygen so that Chen Xin finally eased over. Only then did he have spare time to think about what happened.

　　 There should be no fire in the refuge, because he has not used any open flames at all, and even used an induction cooker to boil water in the past two days.

But at this moment, Chen Xin didn't think much about it. He ran to the garage to pick up the small fire extinguisher in the trunk of the car, and then he checked the various places of the shelter.

　　 However, what made Chen Xin very strange was that the refuge did not catch fire and there was no place for smoking.

　　 Where does the choking smoke in the air come from? The choking gas is obviously something that smells after something burns. Chen Xin absolutely doesn't believe it if there is nothing to burn.

However, when Chen Xin started to check again, he finally found that the smoke came in from the ventilation opening of the shelter, and the smell of smoke entered the shelter from the outside.

　　 This discovery made Chen Xin react. This is a fire outside!

　　 Within two days, has the fire caused by the meteorite impact finally burned here?

　　 But this discovery made Chen Xin feel extremely helpless, because he couldn't solve the problem even if he knew the reason.

　　 That is a big fire that has spread to the entire world. Most of the vegetation will be ignited. Although Chen Xin did not go out, he believes that the mountain where his refuge is located should already be on fire, otherwise it won’t. Let his refuge all smell so strong.

　　Be aware that the ventilation system of the shelter is specially designed so that smoke and toxic and harmful gases will be filtered under normal circumstances.

　　 But the current situation... Obviously, the concentration of external smoke has exceeded the filtering and endurance limit of the ventilation system.

　　 Chen Xin feels helpless and desperate, is he about to be so smoked to death?

　　 Although he prepared a gas mask and an oxygen cylinder, there is a limit to how long these things can be used.

　　In this environment where the smoke is gradually dense, even if the quality of the gas mask bought by Chen Xin is good enough, it can only last a few hours at most. The filter element above must be replaced to ensure the filtering effect, and the oxygen cylinder is even more so. Can only be used for two hours.

Although according to Chen Xin's estimation, the mountain fire outside will not last for a long time and will be extinguished due to the drop in temperature caused by the sky being obscured by dust clouds, it will still last for several days or even more than a week.

Originally, Chen Xin thought that his shelter ventilation system was enough to ensure his survival for such a long time, but now reality has given him a ruthless slap.

　　 Obviously, the ventilation system that was considered to be able to withstand the attack of the mountain fire before, if Chen Xin can’t come up with a solution, after the gas mask and oxygen cylinder fail, he is likely to be like those in the fire. Like the people who were smoked to death, they were smoked to death in this shelter.

Escape? This is obviously impossible.

The smoke had come into the shelter, and it was conceivable that the outside was surrounded by wildfires. Even if Chen Xin opened the door of the shelter and ran out, it would only change from bacon to roast duck on the stove.

And even if he could get out, where could he go?

　　 This fire is not his mountain top, but super fires all over the world.

At this moment, more than 90% of the vegetation on the entire Blue Star has been ignited by the heat released by the meteorite impact. Flames are burning everywhere on the surface of the Blue Star, and there is nowhere to escape.

　　 There may be no flames on the sea, but how does Chen Xin run from the inland to the coast?

　　 Now all transportation systems have been shut down due to the impact of the meteorite. The country may have secret routes, but how can this kind of thing be open to ordinary people like Chen Xin?

　　 And this kind of secret route can be used, Chen Xin ran a hammer and just stayed in the country's secret bunker.

As for official sanctuary, that's really an option.

　　 There is only one core issue here, that is, how should Chen Xin let the closed official refuge open the door for him under the circumstances of the fire~ IndoMTL.com~ You know that even Chen Xin's own refuge gate They are all solid metal explosion-proof doors with a thickness of 12 cm. Let alone knocking with your hands, you may smash them outside with a hammer, and you may not be able to hear them inside. Moreover, for safety, Chen Xin also installed two doors.

　　 One can imagine what the gate of the official refuge should be like.

So Chen Xin never considered the option of escaping from the very beginning.

If you just don't escape, what should you do to survive?

The ventilation system has now reached its limit. Unless I replace it with a new and stronger ventilation system, I will end up being smoked to death in this self-built shelter!

　　 Wait! Chen Xin suddenly shuddered, thinking of a key point that he had overlooked.

He could indeed change to a stronger ventilation system because he has it!

　　 Chen Xin, who thought of the system, hurriedly called out the system interface, and then directed his sight to the ventilation duct of his refuge.

　　 As expected, the ventilation duct in the line of sight lit up, and an upgrade plan was given.

"Natural ventilation system"

　　"Upgrade plan 1: Upgrade filter material, improve air filtration level, increase forced mechanical ventilation function, upgrade requires 100 survival points"

　　"Upgrade plan two: upgrade pipe material, increase insulation level, increase temperature adjustment function, upgrade required survival point 100"

Chen Xin didn't even think about it, so he directly chose the first upgrade plan.

　　 With his determination, the grid-like light appeared again in the realization as it was when the system was started for the first time, but this time the light only covered the ventilation ducts.

　　 Soon, the brilliance dissipated, and the ventilation ducts of the Chenxin Refuge had been renewed and the upgrade was completed.