Radiant ceiling heating and cooling questions
I’m in the process of designing an addition and complete renovation for my current ranch home. I live in Connecticut and I currently sit on an existing slab on grade with no insulation (1950). I will be adding slabs in both the front and back of the house along with a second floor to a total square footage of roughly 2500 sq. ft. I plan on insulating the old and new slabs with 2″ XPS to 2′ below grade along the entire perimeter.
Since this will be a gut renovation I will be saving some of the existing 2×4 walls while framing the new walls the same. I’ll be putting R-15 in the walls and 1.5″ XPS board on the exterior achieving roughly R-22+. I haven’t decided on which vapor barrier I’ll be using under the rain screen siding yet, most likely Tyvek drainwrap or Prosoco-R guard. I’ll also aim for R-49 at the roof line and floor insulation 1st to 2nd is TBD based on the truss design.
Since I’ve worked through most of the exterior and insulation details I’ve started working on the heating and cooling systems. I’ve been really attracted to the idea of hydronic radiant ceilings, but solid information has been a bit difficult to find on design and technical aspects of the system. The best method of installation I can see is to install a breathable radiant barrier below the floor insulation, stapled to the bottom of truss, bellowed slightly between truss bays to accommodate the aluminum transfer plates and tubes. Has anyone seen a installation similar to this? Would it be typical to cover the entire square footage of the ceiling or just enough to provide the correct heating/ cooling? The only pre-manufactured drywall panels I can find for sale in the U.S. is the Raymagic panels by Messana. I don’t fully trust the panel connection and I’d assume the panel cost would be pretty high compared to the plates and pex piping.
Last question relates to cooling with a radiant ceiling. I know based on humidity radiant cooling isn’t the best option for my area. I would need a full house dehumidifier with possible additional duct work while I’d only planned on some duct work for the HRV. In the interest of keeping costs down is radiant cooling viable as an option? Would I be better off installing a multi zone mini split system? I’m really trying to find the best balance for initial costs vs operating costs for my cooling system.
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