After moving from the south to New England, I needed help adapting to no central a/c. We bought several of these fans to place throughout our home. They have done a great job. There are only a few short weeks in the summer that window a/c units are actually needed. The rest of the time, these fans work wonderfully.
The units are dual fan, enegry saving, and simple to install/use. Each fan can be set for intake or exhaust which helps with airflow. in larger rooms, we set them up across the room from each other with one unit set totally on intake and the other set on exhaust to maximize the crossbreeze.
Also, they have a built in thermostat so when the temp drops below the setting, it shuts off. Or, you have the option to just set them to hi or low and override the thermostat.
We have been very happy with these units, and will probably be buying a couple more.