07-22-2020, 03:45 PM
Another item, which may apply specifically to the house I'm planning to build. I am still moving forward on a monolithic concrete dome, built in the Eco-shell style.
Well on page 19 of Hawaii's amendments:
R402.2.5 Mass walls. Mass walls for the purposes of this chapter shall be considered above- grade walls of concrete block, concrete, insulated concrete form ICF), masonry cavity, brick (other than brick veneer), earth ( adobe, compressed earth block, rammed earth) and solid timber/logs, or any other walls having a heat capacity greater than or equal to 6 Btu/ft2 x °F ( 123 kJ/ m2 x K).
Exception: Insulation or R- value for mass walls, indicated in Table R402.1.2, is not required when at least one of the following conditions is met:
1. Walls have a covering with a reflectance of> 0.64.
2. Walls have overhangs with a projection factor equal to or greater than 0. 3. The projection factor is the horizontal distance from the surface of the wall to the farthest most point of the overhang divided by the vertical distance from the first floor level to the bottom most point of the overhang.
3. Concrete, CMU, and similar mass walls are 6 inches or greater in thickness.
So, my feeling is if the county lets me classify the entire shell of the dome as a "mass wall," that greatly simplifies things, for my project.
For every home style, after plugging away at simulations, I still contend that reflective surfaces are much more effective than insulation for interior comfort on hot sunny days.
Well on page 19 of Hawaii's amendments:
R402.2.5 Mass walls. Mass walls for the purposes of this chapter shall be considered above- grade walls of concrete block, concrete, insulated concrete form ICF), masonry cavity, brick (other than brick veneer), earth ( adobe, compressed earth block, rammed earth) and solid timber/logs, or any other walls having a heat capacity greater than or equal to 6 Btu/ft2 x °F ( 123 kJ/ m2 x K).
Exception: Insulation or R- value for mass walls, indicated in Table R402.1.2, is not required when at least one of the following conditions is met:
1. Walls have a covering with a reflectance of> 0.64.
2. Walls have overhangs with a projection factor equal to or greater than 0. 3. The projection factor is the horizontal distance from the surface of the wall to the farthest most point of the overhang divided by the vertical distance from the first floor level to the bottom most point of the overhang.
3. Concrete, CMU, and similar mass walls are 6 inches or greater in thickness.
So, my feeling is if the county lets me classify the entire shell of the dome as a "mass wall," that greatly simplifies things, for my project.
For every home style, after plugging away at simulations, I still contend that reflective surfaces are much more effective than insulation for interior comfort on hot sunny days.