at least one thermal exchange means composed of parallel inner and outer plastic sheet means separated by a plurality of parallel flat ribs oriented normal to said sheet means and fused to said sheet means to form {HEAD ~ a plurality} of {TAIL ~ parallel channels} 
of
at least one thermal exchange means composed of parallel inner and outer plastic sheet means separated by a plurality of parallel flat ribs oriented normal to said sheet means and fused to said sheet means to form { HEAD ~ a plurality } of { TAIL ~ parallel channels }
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 OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL