On Tue, 8 May 2018 21:12:36 -0600, rbowman wrote:

On 05/08/2018 03:23 PM, Clare Snyder wrote:
At least forced air HAS filters - which DO remove a lot of dust fron
the air, and hot water heat is every bit as "dry" as forced air. The
water stays IN the radiators. (or at least is is supposed to!!!)

But the radiator is a convenient place to set a pan of water...
And the hot air duct is a good place to put a humidifier.