Gut renovation in NH – heating/insulation questions
I’m amidst a complete gut renovation of a 1000 sq ft ranch home in central New Hampshire. Our plan is to primarily heat with wood using a wood cook stove in the kitchen. Our “backup” heat source and AC will be a 24k BTU Fujitsu mini split, with two 7k BTU heads in the bedrooms and a 12k head in the kitchen/living room. I’ll be using rockwool in the 2×4 cavities and wrapping with rockwool 2in Comfortboard on the exterior. The west-facing wall will get closed cell spray foam to make a future addition easier. We’ll do blown cellulose in the attic for at least R50. Floors over a full, unfinished basement will be insulated, but the method hasn’t been chosen yet. (Misc.. We’re milling our own wood for the exterior cladding, interior walls and floors and will run a 3.5kw grid-tied solar array).
A bulk load in CoolCalc gave me approximately 21k BTU for heat. The ecomfort.com calculator roughly matched with approx 19k BTUs.
Now, on to the questions…
1) Does the mini-split design and sizing seem reasonable? (Final design of 7/7/12k came from a contractor). Also note the small office on the south-facing wall of the house won’t be conditioned.
2) What can we do to promote air circulation from the wood stove? Our ceilings are low and adding transoms over doors with floor vents might not be realistic. Bedroom doors would be mostly open during the day and closed at night when heating is needed the most.
3) Feedback on the insulation plan would be welcomed.
4) We’ll be using a Kohler 14kw generator for backup power. The specs say that it has a maximum THD of less than 5%, which is generally low enough for sensitive electronics. The Fujitsus are supposedly very sensitive and their technical people have “no comment” when it comes to backup power. I saw another thread where someone had a similar plan and assuming it’s not uncommon to run a mini split from a generator, I’m curious about how it actually works in practice.
Thanks in advance!
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