Couple questions for you "old folks" of Orchidariums

[Ross]

Sorry for the long message title, but I need to ask a couple questions. I am in the planning stages of a new orchidarium (http://www.orchidboard.com/community...read.php?t=366) and am wondering about a couple finer points. 1) I like the idea of Marty's setup where he had the air flowing down over the glass front. How wide should the opening be at the front of the top glass? I was thinking 3/4". 2) can I just have a couple fans blowing across the front glass and achieve the same thing?

All thoughts are appreciated.