Air conditioner units cost a lot of money. Not everyone can afford central air so many are forced to deal with window air conditioner units. Window air conditioner units have helped people stay cool for years. There are good and bad aspects of having window air conditioner units.
The most obvious good is that they help cool you down when it's unbearable hot outside. But they are also cheaper than central air conditioner units. The bad includes the fact that they're noisy, they can break down easily and they sometimes allow hot air to seep in around the sides since they sit inside an open window.
You should judge both the good and bad aspects before you choose to go with a window air conditioning unit. Of course if it's all you can afford, you really don't have much of a choice as any air conditioning system is better than not having one at all.
The Good
There are many good aspects of a window air conditioning unit. The first is that they are fairly inexpensive as compared to a central unit. You can buy one and stick it in the window (another good aspect is that they're very easy to hook up) and you're ready to go. If it breaks, you can probably just buy another one since they are so cheap. They will cool down the room you set it in and eventually it will cool the entire house. They don't use much energy as compared to central units and they will lower your energy bill substantially.
The Bad
The bad part about window air conditioner units is that they're extremely loud. If you've ever heard a central air unit, you know they can be very quiet. Compare that to a window air conditioning unit and it's like night and day. Window air conditioning units also don't cool as much as central units do, or they take a very long time.
The window air conditioning units also sit inside open windows so they sometimes allow warm air to escape around the edges. They can become clogged from dust and pollen and other air impurities and they also dry the air out very badly.
As you can see, the good and bad aspects are pretty even keel. Just remember that any air conditioning unit is better than not having any at all so get what you can afford but realize that having a window air conditioning unit is all about what you make it.