While unitary fans are typically found in schools, or more specifically classrooms, they can be used in other industrial conditions as well. Basically, any situation where there are outside air requirements or room-by-room zoning can benefit from unit fans. Hospitals, nursing homes and other health centers are also very frequent clients of this system. As technology has progressed and improved the ventilation unit, its use remains as popular today as it was two decades ago.

They differ from fan-coil units, unit heaters, and cabinet heaters in that they draw conditioned outside air into the occupied room or space. For the sole purpose of ventilating air, whether or not a designer will apply univents to various buildings or facilities is determined after weighing the pros and cons. There are clear advantages and disadvantages to using unitary fans and these should be considered prior to application.

Advantages of using unit fans:

• It only requires a single unit to provide heating and cooling, as well as ventilation, to a space.
• Very inexpensive and energy efficient because they have the ability to provide room-by-room zoning.
• Outside airflow can be adjusted up to 100 percent outside air.
• They require very little physical space so they do not take up much space and are not obtrusive.
• It can filter noise, odors and other contaminants between adjacent spaces so there is less risk of cross contamination.
• Energy efficiency in its operation, due, in part, to the air side economizers.
• It acts to stabilize a building and increase its reliability because a failure does not affect the entire facility, it is usually limited to one room. Therefore, the entire building is not immobilized when there is a single failure.
• They are very easy and very cost effective to install.
• Maintenance is simple because they are easily accessible for filter replacement and other maintenance.
• They are simple in design and their controls and mechanics can be understood by maintenance personnel of various backgrounds and training.
• The versatility of the univent makes it very attractive. It can be controlled through an automation system that coordinates with other units or it can be stand-alone and simply controlled by a thermostat.

Cons of using unit fans:

• It can be noisy. This is a problem that is not easily fixed.
• A Univent has a limited supply airflow that is approximately 2,000 cfm per unit.
• The systems are part of the architecture of the room. They cannot be hidden and cannot be considered aesthetically pleasing. They are difficult to fit into buildings where HVAC systems and components are not to be seen.

When placed in the right environment, a unit fan is often a welcome component to a building’s HVAC system. Once the pros and cons of using them are weighed and all factors are taken into account, the unit fan becomes an effective and energy efficient addition to the structure.