Why does air still come through the vents on my 02 Civic when the a/c is off?

It seems like air is still coming in through my vents even when I've got the A/C turned off. The temperature of the air in the vents will be similar to whatever setting my A/C is at. If is all the way cold, the air is cold, if its on hot, the air will be hot, even when I've got the system turned off. Does the Civic always vent air into the car through fans? I really notice it when the moon roof is open. Is it my imagination or do other people notice this?

Why does air still come through the vents on my 02 Civic when the a/c is off?
You still have your cowl vents open. The A/C system is ported to the outside through the vents below your windshield. Even with the blower motor off, the air pressure generated by the motion of the car will continue to force air through the system. You can defeat this by selecting recirculate on your main A/C console (this will shut off the middle ducts), and by manually closing off the two side ducts by flipping their dials.





Having your moonroof open simply gives the incoming air somewhere to escape, and thus allowing it circulate in through the cowl faster. With the moonroof and windows closed, the cabin can build up air pressure, and the incoming air flow reduces to a minimum.
Reply:I think it's designed to not be completely shut off like that to prevent condensation from building up and ruining the system. My truck does it but you can stop it by switching from fresh air to recirculating air. Just open it back up when you park.
Reply:I think the Button that shows you the (arrow comming from outside)-in needs to be disingaged. you should see a button with the arrow "re-circulating" for inside the cabin only. this button should be active...





I THINK...LOL





Best wishes!
Reply:well I read everyone answers and It all sounds good BUT they are wrong. On any Honda when you turn off the air it is off. So I would look at it a different way. When you are driving with the air OR heat in recirculate mode. You should not be able to smell car exhaust from the cars in front of you ( get behind an old truck or van Diesel will work fine) If you smell the exhaust you may have 1 of 2 things wrong 1st obstruction in the vent 2 a bad vacuum pod. THAT is all... I think it's the pod. But 1 of you readers was right on about the moor roof and cabin PSI...
Reply:all newer cars do that to keep a small breeze doing put the tempeture meter in the midel it should stop
Reply:i have this on my 96 corolla. It's because you have your air system set to fresh air as opposed to recirculation. Change it over. There should be a switch for it on the console