What is the best whole house humidifier? This will install with the HVAC unit. Thank you

I don't like any humidifier connected to the duct system. If the ducts are metal, rust is a major problem. If they are fiberglass ductboard, mold. For every humidifier I install, I probably take out 10.

I agree with Grady. I just removed a belt type humidifier as part of a sales contract and was shocked to see all the mineral buildup and rust in the plenum. Use a room humidifier.