Check out the Aprilaire 600. It has a control that mounts on the furnace.
The more expensive Aprilaire 700 ( I believe it is) has a unit that mounts
by the upstairs thermostat. I don't mind going down stairs to my furnace to
adjust it. I just set to around 45% and forget it till Summer.


wrote in message
oups.com...
"Isn't there some sort of controller which mounts in the living area
to sense humidity? "

Most have a humidistat that mounts on the return air plenum. But that
doesn't solve the problem of having the unit only turn on when the
furnace and/or blower are running. The humidistat is just another
on/off that will only turn it on when the humidity in the return air is
below the set point.