Will my Air Conditioner unit cool my whole house? Jessica 19 October 2021 08:08 Updated An air conditioner will only cool down the room it is placed in. Related articles What size Air Conditioner shall I get? Can I use a portable Air Conditioner in a room without a window? How often do I need to drain the water tank? Does my Air Conditioner unit double up as a heater in the winter? How do I clean my humidifier?