A window air conditioner unit is probably the most common type of air conditioner. It is also the cheapest. You can pick up a window air conditioner for less than $150 in many cases. Check out our review of the most budget friendly window unit here.
The other benefit of a window ac unit is that you easily install it in pretty much any window. If you have a sliding window (or casement window), you can buy a specially designed window unit that will work in that type of space.
The second type of air conditioner (and an increasingly popular one) is the free standing air conditioner. This is also known as a windowless or portable ac unit. This type of unit does not sit on your window sill. Rather, it is a floor unit that must be vented out a window, ceiling, or sliding door through an exhaust hose. Portable ac units will run you about $300-$600 depending no the size and model.
In recent years, mini split or ductless air conditioning has become increasingly popular. These types of units have two components: the indoor unit blows the air and the outdoor compressor is where the power is. The two systems are connect by thin plastic tubing. These types of air conditioners will run you anywhere from $700-$3000 depending on the size of the space you plan to cool and how much installation help you need.
Finally, the most expensive type of air conditioning is central air. Unlike the mini split units, central air conditioners require installation of ductwork to connect the air handler and compressors. Because of this complicated installation, central air is the costliest.
No matter what type of air conditioner you decide to buy, make sure you get the correct size. To determine what size air conditioner you need, use any one of the many online BTU calculators to get an idea. You will need to have an idea of how many square feet there are in your home (or room if you are planning on getting a window or portable unit). As an example of how many BTUs you might need, a 10000 BTU air conditioner can easily cool a room that is about 300 square feet.
If you are confused about which of the different types of air conditioners to invest in, think about how much you plan to spend and how long you plan to live in your home or apartment. Honestly, there is an air conditioner for every budget and space.