The amount of space you need for a baler to work effectively depends on the size and type of the baler. Generally, you need enough space to walk around the baler, open the chamber door and put in waste, and remove the bales. This should all be possible without blocking any doors or windows in the room.
A baler machine should be placed near where waste is produced and along the path that rubbish follows through your premises. For many organisations, this is in a warehouse, bin area, or at the end of a production line.