Zip or Rigid Foam or Both (& HVAC)
Hello – we are building in Cincinnati (4800 sq ft). Our builder is a fiberglass batt person with no exposure to any of the techniques on the forum, but he’s willing to try new things.
The house will be a 2×6 construction with 10ft first and 9 ft second. We have 2 questions:
1) The thermal envelope – the basic current solution is to use the Zip system with 5.5″ of cellulose in the walls and more in the attic. The improvements I am considering are rigid foam on the exterior and spray foam in certain areas to increase the air tightness. Cincinnati is definitely a moderate but not really cold climate. Am I safe with the above values? I’m going to use an energy consultant to inspect the work and conduct blower tests. He’ll also write in specs for high quality workmanship.
2) One system with 2 zones or 2 systems? – With an air tight home, do you think it will be possible to run on just one 5-ton system with 2 zones for the two floors or is this just asking for trouble?
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