There are basically three primary kinds of air conditioner. These are:

- Window mounted

- Wall mounted

- Portable air conditionerses

Window mounted air conditionerss

These are the most popular of air conditionerss and need to be fitted into the windows. They actually slide inside the opening in a double-hung window. These versions came in two variants - cooling only or cooling and heating together. The positives going for it are its low costs, compatibility with the wiring already present in the house, and ease of installation. However, they are specially designed for double-hung windows so if you have sliding windows you will need to pay for a separate installation kit. The prices generally range from anything between $200 and $800 depending upon the capacity of the air conditioner.

Wall mounted air conditioner

These air-conditioners can be permanently mounted in a wall. A metal sleeve needs to be attached through the wall and the air conditioner chassis is slid on it from inside the room. These air-conditionerses are also available in cooling or cooling and heating varieties. These units are generally better looking than window mounted air conditioners and also do not block the windows in the rooms. The problem is with installation which would require you to make a hole in the wall. If it is a wall of concrete then making a hole in itself would be an effort. One also has to be very careful about any wiring or pipes passing through the wall. Damaging one of them can severely delay your installation. And you would land up with more hassles. However, once installed, these units are easier to remove for replacement and repairs. The prices of these air conditioners range from $400 to $700.

Portable Air Conditioners

These air conditioners are the most user friendly. They don't need to be installed. Just plug it in and it is ready to start work. They also come with wheels. So you can pull them from one room to another. This way you can actually avail the comforts of air conditioner in all your rooms by investing on a single unit. These units however, are priced a little higher than the window or wall mounted air conditioner. Their price varies anything from $700 to $1000.