Heat / mechanical design for PNW near-passive home
We’ve arrived at mechanical design and heat load calcs and we would love some input from this Brains’ Trust! Apologies in advance for a lot of detail.
So first question: For wall system design, we are shooting for R33 and thinking of something like the below composition:
5/8 drywall / 2×4 furred to 2×6 w/ R23 Rockwool / Plywood or zip sheathing / WRB / 2.5″ or 3″ Rockwool board / 3/4″ furring strips / Cedar lap siding
Looking for people’s opinion on the interior Rockwool vs. other alternatives (dense pack Cellulose, double stud wall), and on the exterior, plywood with high end WRB vs. Zip system. Any thoughts / experience between these options and impact on true R-value?
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