Dual compression-expansion pumps and related methods are disclosed. An example fluid pump includes a shaft, a motor coupled to the shaft, the motor to drive a rotation of the shaft, a compressor coupled to a first end of the shaft, a turbine coupled to a second end of the shaft opposite the first end, and a housing including a first inlet, a second inlet, a third inlet, a first outlet, and a second outlet, the first outlet fluidly coupled to the second inlet, the second outlet fluidly coupled to the third inlet.