Floor vents let air out when control is set to OFF

[aharper]

I have a '98 Tahoe that I picked up a couple months ago. When I turn the air controls to OFF the air continues to flow from the floor as if I had asked for it to come out of that location. It doesn't matter where the settings are for vent control... if I turn the speed control to OFF it will always come out of the floor vents!! Ugg. I suppose this isn't a terrible problem in the summer, but in the winter I don't want air coming from there unless I ask it to. Is this a problem with these vehicles? or just mine? TIA.

Andy

[cadmanrjm]

I have had several GM/ Chevys over the last few years and all of them have this set up. i have never been able to identify how to stop the air from flowing through the floor vents. I can say that during parts of the year, such as summer, have the temperature knob rotated to the cooler temp settings. This should minimize the temp change from the outside.

[Danny Demon]

This is called flow through ventillation. A safety feature.

DD