Welcome to the forum, stick around and get to know all the characters..........
Anyway, I usually avoid spec'ing these items, as most are not very good. I have yet to come across one that "heats", rather than "warming the floor" for the bare foot crowd. Even then most don't do a great job at that either. It seems, and rightfully so, that the manufactures of these things are afraid of crossing the "warm floor" to "heating the room via the floor" as the wattage would be too high to have under most floor types. Imagine what it would take to heat a room through a hardwood floor, then imagine that floor bursting into flames! Or, a short in a mildly conductive floor, like some types of tile, stone or concrete.
Anyway, my advise for spec'ing one, is not to.
How-ever, our plumbing friends have mastered this floor "heat" deal, the plumber will need some electrical for the system, so it's not a total loss to pass it to them. kickback?