Do small window Air conditioning units have to be placed outside the window?
They do have to be placed half-way outside to work. Air conditioners work by removing heat from the air and pumping the cool air into the room. The heat that is removed by the air conditioner is released out the back– if you left the whole thing inside, it would just pump cool air out the front and hot air out the back, and the temperature of the room would not change. You’re right that they work like a refrigerator, but refrigerators are only meant to cool the area inside the fridge itself, so it doesn’t matter that the heat exchange is released from the back, the inside of the fridge will stay cold. Becuase any heat that gets into the fridge comes from inside the room when you open the fridge and cool air comes out and hot air gets in, the heat released into the room from a fridge basically won’t change the temperature of a room, but you couldn’t just leave the door open to cool a room– it wouldn’t work.
