HVAC ducting in insulated sealed crawl space?
Designing a new 4000 sf house, two story on sealed insulated conditioned crawl space. Clear overhead is 4 feet.
Wish to use two HVAC units placed in adjacent attached garage, adjacent wall dividing house from garage. Location gives easy duct-way access to underfloor of floor 2 and crawl space under floor 1.
Crawl space foundation walls are ICF, R-22. Floor is heavy sealed membrane covered with 3" slab.
Unit 1 for 2000 sf main floor, unit 2 for 2000 sf second floor.
Ceiling heights are ten feet throughout house, but on main floor there are a number of false beams and lowered ceilings in small rooms and hallway drops that are designed into house to beautify it architecturally, plus provide space for ducting. Lots of space.
Main and only question: Is it appropriate to route all HVAC ducting for floor 1 in the crawl space?