In refrigeration and air conditioning units where a fan draws air through a coil, air flow considerations dictate a flow path for the air as a nominally straight flow path, typically, serially through a grille, the coil and into the fan. The direct air flow path results in a direct flow path for sound produced by the operation of the fan. The result is unacceptable sound characteristics for completely opened and partially closed conventional grilles. This is because the condenser fan is a significant source of noise in a transport or any other refrigeration system. Along with the diesel engine, the condenser fan can potentially be the source of annoyance in a community adjacent to a cold storage warehouse or any other facility that uses these products in quantity, as well as a single unit in distribution markets. The noise also can be an annoyance to a driver in the cab of a parked tractor trailer unit. The diesel engine noise can be reduced through the use of an exhaust muffler and intake resonators. The condenser fan noise, however, has traditionally been reduced only by complete fan/system redesign or by the introduction of louvers into the air stream between the fan and grille. The introduction of louvers into a high velocity air stream can cause self noise, a condition wherein the louvers themselves generate aerodynamic noise in addition to producing some attenuation of the condenser fan noise. As a result, the overall noise characteristics are not changed or are only marginally changed. In addition, in order to achieve significant noise reduction with the louvers, air flow can be compromised, which causes detrimental effects on system performance and generally is not acceptable. On the other hand, fan/system redesign often is not feasible due to space limitations and system performance restrictions.