Air delivery unit

Abstract

An air delivery unit includes a casing, an air delivery device arranged in a fan passage in the casing, and a fan guard that is arranged at an air outlet of the casing and has an air blowing surface having a grill structure and a hollow frame wall portion. An air blowing opening is formed in the frame wall portion of the fan guard. This structure allows the air to be blown also from the opening of the frame wall portion of the fan guard. This reduces the amount and the speed of the air blown from the air blowing surface of the fan guard having the grill structure. As a result, rise of static pressure of the air delivery device is suppressed and noise caused by interference between bars of an air blowing grill and the air is reduced.

1 . An air delivery unit comprising a casing having an air inlet and an air outlet, an air delivery device arranged in a fan passage extending from the air inlet to the air outlet in the casing, an air blowing surface having a grill structure arranged at a position corresponding to the air outlet of the casing, and a fan guard that has a predetermined length along an air blowing direction and is formed by a hollow frame wall portion attached to a portion of the casing around the air outlet, the air blowing surface and the frame wall portion of the fan guard being integrally formed of a synthetic resin, an air blowing opening being formed in the frame wall portion, the air delivery unit being characterized in that:
 a heat exchanger is arranged in the fan passage at a position upstream from the air delivery device;   the heat exchanger is arranged in correspondence with the air inlet of the casing; and   the air blowing opening is arranged in the frame wall portion at a position spaced from the air inlet of the casing.   
     
     
         2 . The air delivery unit according to  claim 1 , characterized in that a plurality of openings are formed in the frame wall portion of the fan guard. 
     
     
         3 . The air delivery unit according to  claim 1  or  2 , characterized in that a rib reinforcing the frame wall portion in the vicinity of the opening is arranged in the fan guard. 
     
     
         4 . The air delivery unit according to  claim 1 , characterized in that the fan guard has a rectangular shape, a recess having a threaded hole being formed in each of four corners of the fan guard, wherein the fan guard is fixed to the casing by passing thread means through the threaded holes of the fan guard and fastening the thread means to the portion of the casing around the air outlet.