I am not going to have any HVAC supplies in the attic. Is a sealed attic and foam still the way to go?
1/2 the house is a cathedral ceiling  with scissor trusses and 1/2 has 8' ceilings w/ attic. Can I do a hybrid foam on the cathedral and blown fiberglass on the rest? If so vented or unvented ?
thanks a bunch
I am in a mixed humid zone...

I highly recommend the use of foam applied to the underside of the roof sheathing in either cathedral or standard attics, to produce a sealed condition. Even without HVAC systems to consider, this system stabilizes the temperature and humidity levels in the attic areas, eliminates the possiblilty of moisture problems in the attic, and gives a conditioned space for storage in the attic area.