Celica Forums General Discussion General Defrost setting requires fresh air not Recirculate?

Is there an important reason why the "defrost" setting (air is directed to the windshield) on my 2004 Celica indicate that "fresh air" should be used and not "recirculated" air? As you know, setting it to "defrost" will turn on the A/C.

Is there some compelling engineering reason why the panel indicates "Use with fresh air"?

Ned

i guess so that it doesnt keep heating the air inside and turning the celi into an oven

The reason you need the fresh air is because it matches the humidity in the car, which is what takes away the 'frost'.

And you guys know the little button on the left isn't defrost for the front right? Thats only for your rear window defrost.

Right as usual.

u can use A/C on recirc and fresh air so what is your point

I never used ricirc air since '88 on any car.
I never want to recirculate any "bad" air into my car or me.
Defrost and AC will help with fogging up.
Full defrost and a bit of windshield blue spray will help more with ice.
I never noticed that turning my dial to defrost full (windshield) or half legs/defrost ever activated my AC. I warm up my car everyday and that is pumping full leg and body or half defrost and half leg depending, never did the AC indicator go on, and it was always hot in my car after 10 minutes even with the defrost button push on for the back window.
Maybe I'm missing something here and I think I am.

To clarify:

When you set "defrost" (air to inside windshield) in my 2004 Celica GT, you also turn on the A/C--no choice.

My question is---is there a compelling reason to use the "fresh air" setting when using "defrost". It is actually written on the console panel next to the "defrost" knob.

Is reads, "When using defrost, use fresh air". Not in so many words, but in symbolic langauge. My question is Why? Will something bad happen when you use "recirc"? Will moisture build up behind the dash or something?

Ned

Well, I think you need fresh air to flow through the car in order to keep the glass from fogging up. Especially in winter. Cold climates.

So you are saying that fresh air is "drier" than air that is inside the car? And drawing the outside air will remove the fogged windows faster?

Ned