Low Temp Hydronic combination baseboard / radiant system – GreenBuildingAdvisor

Hello, 

I’m building a 2200 sq ft single-story ranch home in Maine, Zone 6, R-30 walls, R-60 blown-in flat attic. Half the house (Kitchen, dining, LR, laundry, office) will be on a raised slab foundation (R-10 at perimeter walls and R-10 beneath the slab), and the bed/bath half will be on a full foundation. The basement will not be occupied nor heated, but will be insulated R-15 on walls and R-10 beneath the basement slab.   The mechanical room will be centrally located in the basement, adjacent to the frost wall foundation. 

My heating contractor is suggesting a high-efficiency boiler that would heat a zoned hydronic radiant floor system in the slab end, and use high-efficiency low-temp hydronic baseboard to heat the bed/bath end of the house. 

He mentioned that both would run at ~ 130°F. (I’m assuming for efficiency)

Does anyone have any experience with a system similar to this?  Do you think this is a good approach?  Pitfalls I should look out for? Any and all advice is appreciated.  

Thank you very much!