C wrote:

Small vent holes near the top of each fogged channel would help. I'd put
the holes on the inside surface, that which is away from the weather. The
vents holes would allow trapped moisture a way to escape. The holes would
not need to be any wider than 1/32 or 1/16", I would think. It's worth
trying on one panel before committing to all of them.



When I put up my twinwall polycarbonate panels the manufacturer
recommended that the bottom of the panels be left open and the top be
sealed. This prevents air convection through the panels (decreasing
their insulation properties) while allowing moisture to get out through
the bottom. Sealing the panels can be done either with caulk or with
tape. The aluminium tape is weather resistant and will last a lot longer
than something like duct tape (which has about a 2-month lifetime in
sunlight).

In practice, there are times when moisture collects in the channels, but
the next sunny day clears it out.

If the caulk in the original poster's installation is too thick to
remove or if it is still unsightly after attempts at removal, you could
cut of an inch or two of the bottom of the panel and install a baseboard
(on the inside of the panel).

If you opt for the vent hole approach, I would put the holes at the
bottom, just above the caulk (or maybe even through it), so that they
could also act as a drain in the event that a large quantity of
condensate forms in the channels.