In Pioneer's owner's manual for the 1140HD, they recommend over 19.5" of vertical clearance above the top of the set. This does seem a bit excessive to me.

We plan to have our unit installed in an open-fronted Ethan Allen media cabinet that has a relatively undeep (6" or so) bookshelf overhang, and would have about 3-4" clearance on top. In other words, I never would have thought there'd be a concern about trapped heat in an enclosed space. Anyone have any wisdom to share?