Home air conditioning systems could get a boost in cooling efficiency by using swamp cooling technology.

One of the byproducts of air conditioning in the home is water, which is condensed on the evaporator core which cools the internal air. Rather than dumping or pumping this water away, we will collect it into a holding tank, easily done via gravity feed since the evap core is always at a height above the air moving blower.
By having a small pump which runs when the compressor runs, we can pump this clean water into a pressure distribution rail with atomizing nozzles which will spray the heat exchange coils of the external compressor unit. There will be two cooling actions, the first is that this collected water is cool, and the second is the evaporative heat exchange with the coils.
The electricity used by the pump is orders of magnitude less than that of the compressor, and the added cooling effect would allow the compressor to shut down early thereby savings electricity.