{HEAD ~ Air} is taken in via an enclosure front face from outside the enclosure due to the cooling fans rotation, flows through the interior space of the enclosure, and passes through {TAIL ~ the backboard} 
{ HEAD ~ Air } is taken in via an enclosure front face from outside the enclosure due to the cooling fans rotation , flows through the interior space of the enclosure , and passes through { TAIL ~ the backboard }
HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL