The Sealed Ball Bearing Advantage – Interfan standard fans and blowers all utilize sealed ball bearing construction. While we do provide sleeve bearings on a special order basis, sealed ball bearing construction is inherently a design which will provide more years of service than a sleeve bearing design. Because of the low mechanical load on the bearing system, the lubricant life and temperature are the key factors in determining the life of the bearing and the fan. By using a proprietary lubricant formulation, sealed inside the ball bearing, an advanced blade design to reduce the load, a high efficiency motor and heat sinking construction to reduce temperatures, we are able to offer fans and blowers with superior life expectancies