Tony wrote:
I have a large front porch with a roof about 8 feet up. It is open on
the bottom so you see the sheathing and joists (2x6's). When the sun
is on it the heat really radiates down to the porch area making it
hot as hell even though you are in the shade.

I am considering putting up a "ceiling" but good circulation won't be
easy without a fan. The porch roof extends about 10 feet over the
original roof and shingles of the house so I suppose I could close it
up and add a fan. If I do it I'm thinking of using 3.5" insulation so
there is plenty of room for air circulation between the insulation and
the sheathing.

Any other ideas before I get broiled?

Tony

Forget the insulation.

Radiant barrier. Cheap, 95% effective, easy to install.