High-temperature and high-pressure refrigerant vapor from the compressor flows into the inlet header of the microchannel condenser. The header distributes gas evenly into flat microchannel tubes with dozens of tiny internal channels. Hot refrigerant transfers heat rapidly to aluminum tube walls. Forced air blows through corrugated fins to take away heat. The refrigerant releases latent heat, condenses from gas to liquid, then converges in the outlet header and flows out to expansion devices.