Wally Day asked:
>is it better to "open" the dehydrator up to get as much airflow as
possible, or should the airflow be reduced to a minimum?

If the airflow is opened up too much, the air will rush around the heating
element so fast it will not warm up enough to dry the meat. If the airflow
is restricted, it will get too hot and cook the meat or worse yet, "cook"
your dehydrator! It is best to use the  racks and top along with any baffles
the manufacturer of your dehydrator recommends.
You usually will not get ahead by trying to "Out-Engineer" the engineers who
designed and built your equipment.

Kevin Raper
Piedmont S.C.