Can I leave doors and windows open while operating an indoor unit?
Maintaining the desired temperature in a room and ensuring the efficient running of your air conditioner requires all external doors and windows to be closed, and that any potential way for air to escape easily is sealed.
Having doors and windows open in a room that you are trying to air condition makes it extremely difficult to maintain your desired temperature in that room.
Furthermore, the energy efficiency of your system is affected by how hard it has to work to maintain a temperature.
Open doors and windows will mean your system has to work much harder.