'92 Pontiac Sunbird- Getting no air from vents

I'm getting NO air from vents and everything seems to be working fine. The fan motor is going and I can feel heat coming up vents on dash but I'm not feeling any air. I opened the dash and can see the vent doors moving but theres no air. I just bought the car so I don't know any history other than its in good condition. I'd appreciate any help. It's getting cold in Alaska and I need defrosters!thanks. And the blower motor seems really loud from under the hood.Airwise, I mean.