Is it bad to sleep with an air purifier on in your room?

I bought an air purifier for my room because my dad chain smokes in the house. The box said its for a 16X10 room, but my room is much smaller than that. I keep it on all the time. Is it bad to have it on so much? I thought it may be due to the fact of drying out the air. I noticed my lips dry out a lot. Can it also dry out my nasal and eye areas and cause damage.