2004 santé fe has cold air coming in at the floor on passengers side. heat is on on 2004 Hyundai Santa Fe

is there a door to direct air flow not closing completely?

2 answers
If there is you should find a lever to control it and it's operation would be noted in your owners manual. Does your SantaFe have a dual climate control system? Restrictions in the heater cores on some cars can result in some unequal heat distribution.
poss bad door actuator