HVAC contractors do not know how to design for this home....
I have been round and round with various HVAC guys. Its getting to be quite frustrating. Most are letting their "typical" and "tried and true" mind set cloud over reality and the change in the construction industry. Most are basically ignoring changes and advancements in insulation and building shell tightness. I have done my own calcs in my own programs, have had local utilities do calcs, and my energy assessor/Energy Star/HERS rater also do calcs.
Things are all over the place without much common ground. When I question it, the typical response is "we have never seen something like this, so were not quite sure how to approach it"...
Here is a run down of the home:
Climate zone 6, approx 6900 HDD, design temp -14.
Homes is a 1600 sqft ranch style with full basement. Daylit rooms.
2" XPS r10 underslab, Superior wall r15 basement walls with additional r-19 batts. Main floor walls are r40, 100% thermally broken double stud walls with ZIP sheathing for exterior air barrier and air tight drywall for interior air barrier. Home will be blower door tested with a goal of <.1 air changes pac. there is about glass on the south face triple pane u .20 with shgc of .44. no east or west. north .19.>Roof is vented truss, r60.
Heat loads have been right around 19k BTU including the basement. Cooling around 13k. Other load calcs have been in the low 20ks. HVAC guys have been everywhere from low 20s to 45k! Lots of research will show super insulated homes using hvac as simply as a single mini split heat pump. However I think we want to go with a traditional furnace/hp or ac setup, 2 stage, 2 ton.
Does anyone on here have any experience, thoughts or suggestions on something like this?