You are asked to test a machine that the inventor calls an in-room air conditioner, a big

Question:

You are asked to test a machine that the inventor calls an “in-room air conditioner”, a big box, standing in the middle of the room, with a cable that plugs into a power outlet. When the machine is switched on, you feel a stream of cold air coming out of it, How do you know that this machine cannot cool the room?