I want to install a whole humidifier

[MillWeld]

I live in the Mojave, so added humidity is a winter requirement. Ive been using a Skuttle spray humidifier for 13 years without fail. I have to annually remove the spray head and remove the calcium buildup, but that is the only maintenece and NO cost. Takes about 10 minutes.

Spray Humidifier | Skuttle

With a spray humidifier don't you get calcium salts in your humidified air that deposits in your home? That occurs in my area if the well water is hard.

 

[ADSNY]

If I may chime in...

The humidifier should NEVER be mounted above the furnace's heat exchanger. All humidifiers eventually leak, and you do not want that leakage to fall onto and prematurely rot your heat exchanger. It's much better to have the humidifier mounted on the return side for updraft, supply side for downdraft.

Furthermore, I would never draw the humidifier's water from a hot water tank. Reason being, filth. We don't cook with hot water (ie. make pasta) because of the nasty sludge and slime build-up inside the tank. Why would you want to breathe that? Also, industry professionals are now realizing that we store hot water at 120-125 degrees recommended, which is not high enough to kill the legionella bacteria. That could also factor in when aerosol-izing water through a humidifier.