A heat pump system includes a compressor, indoor and outdoor coils and a four way valve for automatically reversing {TAIL ~ refrigerant} to provide cooling or {HEAD ~ heating mode} of operation 
A heat pump system includes a compressor , indoor and outdoor coils and a four way valve for automatically reversing { TAIL ~ refrigerant } to provide cooling or { HEAD ~ heating mode } of operation
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH