1.5 inch insulation cavity question
If been lurking for some time, and this place is great. This is my first post.
I have a 1.5 inch cavity between my walls, and I am on the fence about insulation. I live in the northeast, and will winter in New Mexico.
I am completely re-doing the walls, and I have the opportunity to either
a) use reflective aluminum material from atticfoil on both the inside of the frame (facing out) and the outside of the frame (facing in) to create an effective reflective system.
B) install 1.5 inch foam board between the walls and simply go with the anti-conduction route.
Given the space of the cavity (we will not be building out the walls), which system would you all recommend.