Roof exhaust fans blow hot or polluted air out of the building to create a safer, more comfortable environment inside. You'll find them in various commercial and industrial applications, warehouses, and manufacturing facilities.
When choosing a roof ventilation fan, you have to consider what type of space you're ventilating (whether it's important to remove hot air and humidity, contaminants, or both) and how large the space is. In a commercial kitchen, for example, upblast fans are essential to remove smoke, grease, and odors; downblast fans can be used in other applications for basic ventilation. Belt drive roof fans are good for large volumes of air and high static pressure, while direct drive fans are better for lower volumes and lower pressure.