There are several companies that manufacturer mini split air conditioners, including Whirlpool, Garrison and Pioneer sold by Amazon.com, and Gree, Ramsond and Amvent available at The Home Depot. These systems split the compressor from the air handler for quieter operation but do not require ducts for air delivery.
Mini split air conditioners are a good choice for homes that do not have an existing duct system for heating, as retrofitting these homes with sheet metal ducts is often expensive. The mini-split systems pump the refrigerant through walls instead of pumping air. Retrofitting a home requires drilling a few holes for refrigerant lines instead of trying to find appropriate runs for ducts.
The mini split systems offer greater flexibility than typical central air conditioning. It is possible to cool an oasis room in the home without having to cool the whole house. When the system includes a heat pump, it provides both heating and cooling for the room.
Mini split units also offer advantages over window air conditioners. They do not block the window and allow it to remain usable for natural ventilation. The mini split system does not have the home security issues of window air conditioners. A permanently installed thermostat controls the temperature in the room to ensure the greatest energy efficiency.