2×6 framed floor on top of radiant slab – GreenBuildingAdvisor

Hi all, what are your thoughts on a standard radiant-heated slab (4 to 6″ thick with radiant tubing inside of it with xps rigid foam and vapor barrier underneath) with a 2×4 or 2×6 pressure treated framed floor on top of the slab. Then an OSB subfloor on the PT joists, and finally a finished floor (engineered hardwood, tile, or vinyl). Do you think the radiant heat would still be effective with this air gap between the slab and the floor? Would it somehow lose efficiency? I’m not an engineer, but my gut feels that this should work fine since the slab will still operate as a thermal mass, and the heat has nowhere to go but up. Thoughts?

I like this idea because the sleepers provide space to run wires, plumbing, etc.