In the second operational position, the first register provides for {TAIL ~ atmospheric fresh air intake} at the compressor and supplies the residence with {HEAD ~ the turbine discharge air} 
In the second operational position , the first register provides for { TAIL ~ atmospheric fresh air intake } at the compressor and supplies the residence with { HEAD ~ the turbine discharge air }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD