Unlike whole-house humidifiers that are furnace-mounted, console humidifiers are not connected to the main water supply. Instead, these include a tank to supply the mist of humidity in a room. For this reason, console humidifiers are not much efficient in humidifying your open floor plan that has a living room ceiling (opening to the second floor). Use a whole house furnace humidifier in this case. When it comes to placing a portable console humidifier version, remember these are much bulkier than your regular table-top versions. Hence it is good to place them on a floor (and not on the nightstand) at a location that is far from the reach of your kids and at-home pets.