Carrier humxxlfp1518-A

I have the whole house humidifier posted in my title in a house I bought this summer. Last night was my first experience with a real cold and likely dry evening. My humidifier seems to kick in and run when my furnace is not running. It makes a nouse when it does this, one as loud or maybe slightly louder than my furnace. Is it doing what it is supposed to or should it only be kicking in when the furnace does? Thanks in advance for ant guidance.