Most Parisian buildings don't have heat and cooling ducts. Even the French President has to use a portable AC with an ugly exhaust pipe in his residence at the Elysée Palace.
If you decide to storm the Bastille and install an air conditioner, you have a long road ahead
Step one: save a lot money for long and expensive drilling work
Step two: make sure you live in a place where you have a terrace or a balcony, to have enough space for an evacuation pipe
Step three: write a formal letter to the building manager explaining your need for an AC
Step four: the residents of your building will decide during the annual vote whether you deserve an AC
Step five: move to a different country and never look back