"the frame is enclosed" - does that mean in the plan or the job is already done ?
There are sprinkler heads on the market which look like light sconces or other ornamental ceiling or wall mounted stuff.
If the sips are not yet ordered then Thermocore will include your sprinkler 1" pipe given a verified copy of the plans. You have to put some thought in non-intersecting with electrocal conduit and accessible exith at the edge of the panels. Talked with Richard Egan of Thermocore on this very topic at the Eastern Conf just concluded.
Work safe, have fun.
