Usually the longer the fan blade the greater the pitch of the blade. Along with a higher pitch usually comes a bigger motor which will also determine the strength of the air flow. If you have a large room you are trying to cool off, go with a high blade pitch. Another important distinction is whether the fan is made to hang down from the ceiling on an extension. This type of fan is usually put in a room with a high ceiling.
Ceiling fans can come with a light in the middle or without.
Having a light in the middle is usually an essential aspect if the fan is going in a bedroom. Installation of a ceiling fan is more easily done with two people. It also requires some knowledge about electricity and must be done with caution to avoid an electrical shock. It is possible to put in a ceiling fan where there is no previous light fixture, but that is more complicated and will not be discussed in this article. The first step is to turn off the electricity on the light fixture you will be replacing.