Package Terminal Air Conditioners or PTAC's are entirely self contained. They are commonly used in a commercial setting such as a hotel. With a PTAC the unit goes through the wall with hot air being vented outside, circumventing the need for any duct work. They are usually less expensive and save energy by only cooling each room separately.
Casement Air Conditioners are specifically designed to fit the dimensions of a casement window. They have the same functionality as any standard unit but can be used in windows that are taller than they are wide.
Portable Air Conditioners are very energy efficient because they do not use Freon to cool the air. They use the cooling effect of water evaporation. When water evaporates it takes away heat. This is the same reason why sweat cools you off on a hot day. When warm moist passes through these units the water is then evaporated off taking heat with it. This cooler less moist air is blown into the room with the water being deposited into a reservoir and the hot air being vented out of your wall, window or sliding door. Some units require manual removal of the collected water while some unit will do this automatically be sure to check your owner?s manual.
Mini Split Air Conditioners are very convenient because they combine the efficiency of cooling each room separately with the power of a central standard air conditioning unit. In this style the main air conditioning unit sits outside venting all exhaust out of your home. The outdoor unit linked to an air handling unit or "zone" that is located inside any room(s) of your choosing. With multi zone units you can choose up to four rooms to cool with one outdoor air conditioner. Since each zone has its own thermostat you can more precisely control the temperature of each room in your home.
Through the Wall Air Conditioners are a good way to have a unit with standard air conditioning capabilities without having to run it through a window. This preserves natural light in the room. These units are literally built right into your wall and sit in a frame that vents exhaust outside with cool air blowing inside. Be sure that your home has the necessary infrastructure to accommodate these units.
Window/Wall Air Conditioners provide you with flexibility because they can either be installed into your window or through your wall. This allows you the option of changing where you want your air conditioning unit with much more ease than a more permanent through the wall air conditioner.