I noticed that there are a lot of posts regarding humidifiers but I can't find answer to my question, so here goes...
I recently contacted a local HVAC business to get an estimate on a humidifier for my gas forced air furnace since I can't take the lack of humidity anymore. They are recommending an Aprilaire 400 after coming on-site. Checking out the specs on Aprilaire's website, everything looks pretty good, but I haven't really found any reviews on this particular unit. The 600 seems to be much more popular. Is there any reason to not consider the 400?
Also, I was thinking that this style of humidifier might be fine while we're home and awake, but what is everyone's experience when setback thermostats are brought into the equation? At night our furnace won't run unless it is really, really cold outside since we set our stat back 8 degrees. In these types of situations I'm thinking that the evaporative pad style humidifier may not work out too well. Any thoughts?
Finally, who knows what the future will bring. Our furnace is 14 years old and I was told that it is in excellent shape during this year's inspection, so assuming we get another few years or more out of it, we may look at hybrid solutions or possibly geothermal if it becomes more affordable. Would the 400 work okay with a heat pump?
Unless any of this isn't of any real concern I suppose I'll have to look into steam humidification instead. If you can address any of these concerns I'd appreciate it.