The difference between TEAO and TENV motors is mainly about how they are cooled and where they can be used. These abbreviations describe enclosure and cooling types that are important when selecting motors for exhaust fans, industrial blowers and mining ventilation fans.
TENV stands for Totally Enclosed Non-Ventilated. A TENV motor has a sealed enclosure that prevents free exchange of air between the inside and outside of the motor. It has no internal or external fan blades to force air over the frame. Cooling relies on natural convection and radiation from the motor surface to the surrounding air. TENV motors are simple and robust, often used where dust, moisture or corrosive fumes must be kept out of the windings, but their continuous power rating is limited by how much heat can be removed without forced ventilation.
TEAO stands for Totally Enclosed Air-Over. Like TENV, a TEAO motor has a totally enclosed housing to protect the internal parts from contamination. The key difference is that a TEAO motor is designed to be cooled by an external airflow passing over its frame. In fan applications, this airflow is typically provided by the fan impeller itself: the motor is mounted directly in the air stream that the fan moves. Because of this forced cooling, a TEAO motor can usually deliver more power in the same frame size than a TENV motor.
In ventilation and exhaust fan systems, TEAO motors are common when the motor is located in the airstream, such as in some axial fans and roof exhausters. The moving air keeps the motor cool during operation. However, the air must be relatively clean and at a suitable temperature; otherwise, dust build-up or hot gas can damage the motor. TENV motors are used where the motor must be protected from a dirty or corrosive airstream and is mounted outside the duct or fan casing.
For mining and heavy industrial fans, enclosure choice is critical. In dusty, explosive or corrosive environments, motors may also need additional certifications and surface temperature limits. Engineers must ensure that a TEAO motor will always have its required cooling airflow whenever it is running and that it is not placed in stagnant or recirculating hot air. For TENV motors, derating may be necessary if ambient temperatures are high or if the motor is installed in a confined space.
In summary, TENV motors are totally enclosed non-ventilated units cooled by natural convection and radiation, suited to lower power ratings and protected locations. TEAO motors are totally enclosed air-over units designed to be cooled by external airflow, making them ideal for many fan applications where the air is clean enough and the motor sits in the main ventilation stream.
