MODEL RELEASED. Air conditioner manufacture. Female technician inspecting part of a heat exch- anger as part of quality control. Completed heat exchangers lie in the background. The heat exchanger will remove heat from a building as part of an air conditioning system. The heat exchangers are comprised of many metal vanes to increase their surface area, and so improve its heat transfer efficiency. This system removes heat by pumping fluid through pipes in an indoor heat exchanger to pick up heat. The fluid is then pumped to an outdoor exchanger to cool it down before being returned to the indoor exchanger.