BPHE works by transferring heat between two fluids at different temperatures without mixing them. A series of metal plates are brazed together inside BPHE, with each plate having a pressed pattern that creates channels for the fluids to flow through.

As the fluids flow through these channels, heat is transferred from the hot fluid to the cold fluid through the thin metal plates, following the principle of thermal equalization. The pressed pattern on the plates creates turbulence in the fluid flow, which enhances heat transfer efficiency.