Porch addition - ceiling insulation
 

I added a 3 seasons porch to my existing cottage, but now like it so much I'd like to have year round use. Porch is 8' deep, 32' long, 7:12 pitch open ceiling with 2x6 rafters (16" on center)...connected to anchor on house. Porch just has storm windows on it. I added wiring for 2 6' baseboard heaters. Floors and walls are insulated and finished. How do I insulate in the rafters so there's proper air flow/venting. Is it possible? There is a 1' overhang of end of porch roof.

Insulate heavily and maybe use a Heat Recovery Ventilator? From what I've read, they're touchy.

Using the 10w/sq. ft. rule of thumb your baseboard heat should total 2600w, give or take.

This may come in handy
http://www.degreedays.net/

I would add 2x3 to the bottom of the rafters to allow 6" insulation and a gap above if you can rework the flashing against the house to make a vent across the top. If not your best bet will be closed cell spray foam. And welcome.