I think the right term is ventilated air space. It is basically a double wall with metal strips between which make a gap between the two sheets of cement board. The second sheet is placed a bit higher which allows cold air to come in from below, heat up, and exit from the top - making a circulation of air. This should lower the temp of the wall if I am not mistaken.
No need to go all the way to ceiling... and I like the way this looks.
No need to go all the way to ceiling... and I like the way this looks.

wondering whether there was a reason other than aesthetics.![[Hearth.com] How do I do my stone veneer correctly? [Hearth.com] How do I do my stone veneer correctly?](/talk/proxy.php?image=http%3A%2F%2Fi258.photobucket.com%2Falbums%2Fhh270%2Fubgone%2Fcabin%2F2013-09-25190942_zps10fe0e94.jpg&hash=8cde1cb2307b94126bb9dd073b58c68c)
![[Hearth.com] How do I do my stone veneer correctly? [Hearth.com] How do I do my stone veneer correctly?](/talk/proxy.php?image=http%3A%2F%2Fi258.photobucket.com%2Falbums%2Fhh270%2Fubgone%2Fcabin%2F2013-09-25190923_zps5b6b4243.jpg&hash=9603df27ec51f111a03ab8fffe70430e)
