Are there any specific application methods that will extend the life of an Axial-flow Fan?

Yes, the following methods will help extend the lifetime.

Keep the ambient temperature (i.e., temperature of the Fan itself) as low as possible.

→ Use the Fan at the inlet.
Do not subject the Fan to shock. (The bearing is especially susceptible to damage from shock and has a major effect on the Fan life.)
As much as possible, do not expose the Fan directly to dust and other airborne particles.

→ Install a filter.