Comment by IX-103

Unless you're in a dense urban area, the effect of your air conditioners on neighboring houses is negligible. There's so much other thermal reservoirs around (like the ground and plants) as well as circulation from the wind that the extra heat from the air conditioner has only a small effect on the environment.

Compare the volume of your house to the volume of area around your house (including several hundred feet vertically, since that is easily part of the circulation). If you're cooling your house 20 degrees then that would correspond to heating an area 20x the size by 1 degree. How many times bigger is the circulating area around your house (100x? 1000x?)?