Whole House Coolers
Whole house systems are large and expensive both to purchase and install as well as to run. The running costs of large systems has reached such heights as to deter many from co0nsidering this option.
Smaller individual room fixed air conditioning units are more popular because you only need to fit as many units as you really need. Bedrooms and the living room are the main recipients of these units which fix to an external wall in the room and connect to a venting unit on the outside wall. These units still cost money to run and if you have several units running at the same time, the power consumption can be considerable.
You can also buy individual portable air conditioners which as mobile units that you can move from room to room as you go. These represent a lower fuel usage because you only run one or two units at any one time depending upon how many people live in your home and how many rooms are occupied at the same time.
Here is an excellent article that is well worth reading up on how to save money on air conditioning. The article details the many benefits, uses and provides a wealth of resources if this type of air cooler interests you.
You can also get evaporating cooling units which extract moisture from the air in a room and reuse it to cool the air that it blows out. These are cheaper still to run and they do not have any harmful CFC refrigerant gasses to worry about.
Whichever kind of system you end up choosing to go with, you need to evaluate the overall costs of buying, installing and running your system from year to year, You will have to factor in the regular increase in the cost of power as prices are never going to go down!