The cabin conditioning system can include a cabin air loop, a refrigerant loop, and a set of thermal rejection components. The system can optionally include a phase-change fluid loop. However, the cabin conditioning system can additionally or alternatively include any other suitable set of components. The cabin conditioning system functions to condition a cabin interior (and/or an air volume therein) of a vehicle, such as an atmospheric and/or space-flight capsule. Additionally or alternatively, the system can function to reject heat from the vehicle interior and/or vehicle power systems (e.g., avionics components thereof). Additionally or alternatively, the system can function to maintain the humidity of air within the cabin interior. However, the cabin conditioning system can include any other suitable components.