Looking at ventilation fans industrial facilities generally install, you will find that they are similar to residential fans. In most cases, the only real difference between residential duty fans and industrial fans is how robustly they are put together.
Industrial Stand Fans, A Basic Ventilation Fan
One of the most common types of fan is the portable stand fan. Technically, these are “axial flow fans” where the majority of the airflow moves parallel to the shaft of the motor. In residential-grade stand fans there is often a gear train which allows the power head to oscillate slowly back and forth. This helps to distribute the airflow through more of the room. However, the oscillation gear train is a point of potential failure, so it is sometimes left off of industrial-grade stand fans.
Whereas the residential stand fan has few metal parts with the exception of the motor and the tube of the stand, the industrial stand fan has very few plastic parts. As a result, the industrial fan is heavy as well as a heavy duty item. While it may not oscillate, it is powerful enough to move a rather significant volume of air. It is designed to provide a comforting and cooling airflow for workers. It may be used for other duties such as drying wet floors, clearing paint or adhesive fumes among other similar uses.
Centrifugal Fans
If your home has central heating and air conditioning, the system probably has a centrifugal fan at its heart. Centrifugal fans like the type that Customfans of Australia designs, are common in industrial settings because they are relatively inexpensive but capable of moving air at a high velocity. The heart of the centrifugal fan is the impeller, sometimes called a squirrel cage because it resembles the exercise wheel used by rodents kept as household pets.
When the squirrel cage spins, the blades draw the air from the center of the cage. This creates a low pressure zone, and ambient air will rush in to fill it. This is sufficient if the fan application is simply designed to draw air from a space, but if a shroud is placed around the cage, the air rushing away from the spinning blades can be directed. Because it has high velocity, the air will travel a long way through ducting without the need for a booster fan midstream.
Tube Axial Fans
One sort of fan that is common in industrial settings but less obvious in residential use is the tube-axial or ducted fan. Normal axial fans lose a lot of efficiency because some of the air that they blow “falls” off the tips of the fan blades. This is actually a common problem in aerodynamics, and it is the reason we see small vertical winglets at the tips of airliner wings. If we mount a fan inside of a shroud or tube, the air that would normally fall off the tips of the blades will be directed in the direction of intended airflow. Placing the fan inside the shroud also allows the blades to be set at a higher pitch or angle to the shaft.
Tube axial fans are becoming more common in industrial ventilation and cooling applications. They are a long time favorite of fire and rescue workers for de-smoking structures. Tube axial fans seem less common in residential applications, perhaps because of the size of the units we find in home and office settings. Ventilation fans industrial use including tube axial fans in industrial applications are employed across the industrial spectrum; powerful units housed in steel shrouds, similarly, it is the very same technology employed by the very efficient 2-4 inch fans used to cool home computers.