A furnace mounted
is my preference. I change the pad before the winter, and clean the frame with vinegar. It costs $8. No fan, just drip type. I have the water valve on the supply line opened just enough so not much goes down the drain. Our ambient humidity stays around 55 or 60%. Minimal window sweating.
I remember the Sears Best furnace power humidifier we had growing up. It was huge, and mounted in the heat duct just above the new gas furnace my dad put in. It had an electric fan, and automatic and manual limeguard. The case was heavy plastic, the control stamped steel with steel conduit.