If you’re hunting to eat, the express purpose of hunting is to acquire meat.

Then go to the store. If you’re hunting, assuming it’s not for sport, your express purpose is to kill something to eat. You don’t get meat without the death. Likewise, the express purpose of A/C is to move heat outside. You don’t get the heat out of the inside without releasing it to the outside.

The definition of “express purpose” is focusing on the result.

The laws of thermodynamics are not a side effect. Again, you cannot “produce” cold air, it cannot be the purpose because it is not physically possible. The result is transporting heat from inside your house to the outside atmosphere. That is the express purpose of the air conditioner.