Mini-Split Sizing and Layout Questions
Upcoming new construction in southeastern NC (CZ3).
52′ x 40′ rectangle. Insulated, elevated slab. Simple gable trussed roof. Wrap around porch on two sides.
2×6 @ 24″ OC framing with dense pack cellulose in the walls. Vented attic with blown cellulose to at least R-38. All windows and double outswing patio doors have a U-factor of 0.30. Air sealing goal is between 1 and 1.5 ACH50. Front and side door are estimated at ~R-5.
I would like to use mini-splits for the entire house. I would prefer all ductless, or, if necessary, a combination of ducted and ductless.
I’ve done load calculations with CoolCalc, BEopt, and by hand and all three results are extremely close. The total house block loads are…
14000 Btu/h Cooling (2 occupants and 2400 Btu for appliances)
18000 Btu/h Heating
I used CoolCalc for room by room and then did it by hand also. Again, results very close. The attached floorplan shows the room by room loads, which add up to 14000 and 18000 heating and cooling respectively. Do the total block loads and the room by room numbers sound reasonable for the given details?
Considering the layout, how could mini-splits be sized and placed most effectively?
The kitchen, dining, and living room is one large open room (40′ x 17.5′). The total heating load for the entire room is just over 6kBtu/h. Is it possible to use a single head unit for the entire room, or would two heads be needed due to the length of the room? The hallway opens directly into the large room. The dotted lines are some wood beam framing around the opening.
Can a single unit be used for the hallway and guest bedrooms? A single head unit for the master suite (bed, bath, and closet)? What to do about laundry room?
Thank you guys for the help and advice so far.
Hopefully Dana will weigh in… 🙂
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