Can someone refresh my memory as to why 240V electric baseboard heaters are
"more efficient" than 120V? In my application I am looking at install one
750W electric baseboard in a bathroom, on a dedicated 20A 120V circuit, but
the heating man strongly suggests I use a 240V model. Problem is the
breaker box is completely full, and I'd have to run a subpanel just for this
circuit if we go 240V.

My other concern was GFCI protection - at 120V I could install a GFCI
breaker in the panel to protect this heater circuit -- do they even make
240V GFCI's for the panel (GE)? I am a little bit worried about someone
splashing water from the sink or a toilet overflow going into the electric
baseboard heater -- the baseboard will be within inches of each.

Last item - electric "hydronic" baseboard sounds better than the standard
electric baseboards - more even temperature - but I also saw a website say
the hydronic units were "safer" - why? because the heating element is
enclosed in a fluid tube and not exposed?

Thanks.

-- Paul