The grain dryer 10 further includes {TAIL ~ a heating unit} 40 which is operable to draw ambient air from the environment, heat the ambient air, and advance the heated air into {HEAD ~ the plenum chamber} 28 
The grain dryer 10 further includes { TAIL ~ a heating unit } 40 which is operable to draw ambient air from the environment , heat the ambient air , and advance the heated air into { HEAD ~ the plenum chamber } 28
OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH