“Wait,” you’re saying, “what’s a packaged HVAC unit? Is that like a window AC?”
Well, sort of. A packaged HVAC unit is a cooling system or heat pump where all the components are contained in a single cabinet. The compressor, the evaporator coil, the condensing coil, the fans and motors—the works. The opposite of a packaged unit is a split system or a mini split system, where there are separate indoor and outdoor units. For example, the most common type of central AC found in homes is a split system with an outdoor condenser and an indoor evaporator with an air handler that sends the cooled air into the ducts.
When you are looking for a new air conditioning system to cool down your house, or as part of planning for a new house, you may notice that one of your choices is a “ductless mini split heat pump,” which offers ductless cooling. These systems have enjoyed years of popularity in Japan and Europe, and now they are starting to show up in more homes in the US because of the many advantages they offer. No longer needing to use ducts eliminates a major cause of energy waste in an HVAC system, removes a source of air pollutants, and allows a homeowner to control the temperature in different parts of the house without affecting the other parts.
The internet has made it easy for people to access information on just about any topic with only a few keyboard clicks. But it also makes it easy for people to access misinformation as well, and many myths have now spread far and wide because of the web.
Spring is a good season of the year to take stock of an air conditioning system in a house and ask a few tough questions, such as 
Are you concerned about 
