At the beginning of the game, the easiest way to pressure a small base with breathable gas is to use the Life Support System. It consists in a pressurizing system equipped with N2 + O2 bottles to pressurize and cool the base, and a powerful electrical heater.

• The cold gas is released at 250K (-23ºC) until reaching a pressure of 50 kPa in the base;
• The heater turns on to slowly heat the base until 293K (20ºC), this happens after a couple of in-game days, then it keep the base above this minimal temperature;
• When the base atmosphere is too hot, the Life Support System will release more cool gas to keep the temperature below 303K (30ºC).

The Life Support System will not cool the base definitively, it has a limited content and is designed for a 6x6 room. When empty, it can continue heating the base when needed, but the colony will have to find other way to pressurize the growing base/station.