When we boil water at sea level, the temperature is 212F (100C) no matter how much heat energy (measured in BTUs) we may add. The water will flash to steam but the steam will remain 212F. We could put 9000 BTUs of heat in but the temp stays the same. But when we condense the steam, those BTUs will be released and we can and do measure it. This is called LHV or latent heat of vaporization.
Air conditioning works on the same principle. The refrigerant has a very low boiling point and flashes to gas during which it can absorb huge amounts of heat energy in the evaporator without heating up. It then travels to the compressor to be compressed into a high pressure gas so that when it moves to the condenser, it will immediately lose pressure and flash to a liquid state giving up all those BTUs. The blower fan will then blow this heat outside. The condensate will then travel to a thermal expansion valve to be metered back into the evaporator again to maintain the same temperature in the compartment that is being cooled.
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