This model works well and is a replacement for one that was 15 yrs old. The new one is quieter and fits the same cutout as the old one, but the humidistat requires a 3/4 in hole in the return air duct. One note is if it is set to automatically turn on the blower, it will run to keep the humidity levels constant, important for a loose old house like mine. I connected mine to hot water, and it really gobbles up the water to the point that the condensate pump runs every minute or two. Either you use cold water which makes the heater run longer, or hot water which makes the water heater run more often but improves efficiency. Its a tradeoff.