Moisture and energy efficiency in ICF Cape Cod design
My wife and I are designing and building a Retirement home in King George, VA (almost in view of the Potomac River). I'm concerned about managing moisture in what I hope to be a very energy efficient home for the long run.
The home is ICF in the Basement and on first floor (1700 ft-sq on 1st floor) and then has a room truss above for a second floor with two rooms and a bath room. Front of house has a direct southern exposure. The first floor is also planned to be an ICF "Lite Deck" concrete floor that I plan to run radiant heating tubes, while cooling is "planned" to be via Mini-Split HVAC system. My room truss Cape Cod style 2nd floor spaces are planned to be insulated with a combination of some type of foam board (EPS or XPS or ???) between studs and some blown-in insulation past the room-truss rooms (R-50ish); I plan to have a Ridge Vent and soffits with the FHB recommended 60/40 Air Intake to Air Exhaust to create a slight Positive Attic Pressure.
Since I intend the home to be super tight and with a good effort to eliminate air leak sealing in the challenging Room Truss spaces above the first floor; lots of spray foam and acoustical sealant...
I am starting to second guess my approach and am also worrying about a super tight home and moisture build up ... I am trying to study as many FHB and GBA articles as possible but I really don't have a handle on what to do in my design or design requirements to drive out moisture (especially in the hidden attic roof areas). Oh, I also plan to install some kind of Air to Air Heat exchanger that I was thinking of providing outside air via an earth tube to pre-heat or pre-cool the air (the tube would run around the foundation footing area but above the drain tile tubes).
Please help me with my design nervousness as a basic concept (ICF and such; good/bad or things to consider) and also what I could do to ensure I have risk areas like moisture build-up well mitigated by design. I guess in the moisture concern I am worried about condensing air. Since I am second guessing myself ... any other things I should consider for an energy efficient home for the long haul...
Thanks so much,
Eric & Christine (worry warts) :-)
PS - I know ... that's a lot of worries for one "question"
Posted Sat, 09/21/2013 - 17:02
Edited Sun, 09/22/2013 - 05:35
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