hot air comes through vents when heater is off?

[santino1932]

i am going to try my best to explain this problem. when i am driving i can feel hot air coming out of my vents when the heater is off. its not blasting out like if it was on but you can feel warm/hot air coming through.the heat worked fine in the winter and the vents open and close properly. but its summer and i don't need the extra heat. i put the dial at 60 degrees to see if that would do anything but still hot air is coming through the vents when its in the off position. i checked everything no leaks, pressure is fine hoses are hot so thermo and heater core are both good anti-freeze is at level and clean. a/c is out of freon so i need to fill that. its a 98 olds bravada with climate control heater
its been in the cold mode, still hot air is coming out the vents. and please keep in mind its turned off so its not blowing out like it would when its on.