There are many possible ways of categorizing air conditioners. You can do it by size of the room it is able to cool, by price, by placement, by brands, by built-in technology, by additional functionality - cooling only or also heating, dehumidifying, etc., or as it is most common in AC industry, by basic form.
One of the criteria for selecting air conditioner is based upon ductwork. Ducted air conditioners (central installation) can cool down entire house or building through ductwork, while the majority of ductless air conditioners are made for cooling one room only (except mini-splits, which are also suitable for cooling many rooms), but without the need of ductwork.
Other criteria for selecting an air conditioner can be the number of rooms you would like to cool. Central air conditioners are best solution for cooling entire house or building. Also mini-split air conditioners support multiple zone cooling, you just have to select the right model. If you have to cool down only one room, consider room air conditioners instead. You can easily build them in the window or wall and they use at least 10% less energy than central units.
The third and most selective criteria when buying an air conditioner is its basic form or type of installation required. According to these criteria ACs are categorized in central, mini-splits, PTACs, window, through-the-wall and portable air conditioners. The latest are more or less a supplemental device's for sporadic cooling needs, but their popularity is constantly increasing.
Portable air conditioners are freestanding units, mostly with casters, to that they can be easily moved around, wherever they are needed. They are becoming more and more popular, because they are flexible and small.
Portable air conditioners operate similar to window or through-the-wall air conditioners. The refrigeration process cools the indoor air and exhausts the heat and moisture to the outside.
What some people mix is portable air conditioner and portable air cooler (also known as evaporative air conditioner). They work on different principles, they have different influence on the room humidity, experts recommend them for different environments and finally, they are in different price ranges.
Room air conditioners can be real energy savers over central air conditioners, if you only have to cool just one room. Room air conditioners came in two types as Window air conditioners and Wall air conditioners.
Window units are the most popular type of room air conditioners. This is probably because of their easy and fit installation in most hung windows; some fit in sliding windows as well.
Through-The-Wall units are another type of room air conditioner, which is a little more complicated to install, since it requires a hole in the exterior wall. Once installed, they can bring some advantages over window units, like less space required and more secure fit for example.
Packaged Terminal air conditioners are best known from hotels and hospitals. These self-contained units are mounted on the external wall and usually have large buttons for turning the temperature up or down. Because the evaporator and condenser are located in the same unit, PTACs are noisier than mini-splits, but they are more efficient than window or wall air conditioners. Even if they are mostly used in commercial buildings, you can also use then in your home or office, especially if the room you would like to cool does not have a window.
Ductless Mini-Split Air Conditioners use conduit to carry the refrigerant and the power instead of duct. Mini-splits have a set of separated indoor air-handlers, to cool each zone of the home separately. Some ductless mini-split air conditioners can work as heat pumps, providing you heating and cooling functionality.
You should not mix this type of air conditioner with split-system type of ducted central AC! Be sure, that seller understands you when shopping.
Central air conditioners (also known as ducted split systems) are a dominant form of air conditioning in many new homes. You install central ACs with the purpose of regulating the air temperature and climate control in a building as a whole.
Since the installation requires ductwork, many people with existing homes rather choose ductless mini-split and room (window/wall) air conditioner systems. Another important factor to consider with central air conditioners is the inefficiency of ductwork, which can result in higher energy bills.
Central air conditioners come in two types, split-system or packaged units.