A window-type aircon is the only type that a handy homeowner might reasonably install without professional help, as it involves sliding the unit into a prepared window or wall opening, securing it, and plugging it into the appropriate outlet. However, split-type air conditioners should never be self-installed by someone without proper training, as incorrect refrigerant handling, improper flaring of copper pipes, and faulty electrical connections can damage the unit, void the warranty, and create serious safety hazards including refrigerant leaks and electrical fires. Even for window-type units, consulting with a technician to confirm proper placement and electrical compatibility is advisable before proceeding on your own.