How to use defrost only with FAN?

Every Hyundai Accent owner knows that whenever you turn on the air
blow to the windshield, the AC turns on Automatically. Is there a way
to switch this off so that I can save on gas?

Thanks

 

I dont have an accent, but I have an Elantra GT that does the same thing, I
just wait till the windows clearn off and push the A/C button and turn it
off and the blower still goes....

 

Relax. In the old days, the A/C compressor running ate up gas. Now,
it might take maybe 1 mpg off your mileage. Not enough to lose a lot
of sleep (or money) over.

 

In the Pacific Northwest we like the AC on to dry out the air and clear the
windows more quickly.

 

No there isn't a way to shut it off. The AC comes on to dehumidify the
window area, thus clearing it more quickly.
You won't notice any change in gas mileage even if you could turn it off.
The AC automatically turns off (disconnects the compressor drive
momentarily/as necesary) during periods of heavy load, like during
acceleration or going up steep hills, etc.

 

"No there isn't a way to shut it off. The AC comes on to dehumidify the
window area, thus clearing it more quickly."

Clears WHAT more quickly? The ice? Don't think so!

 

When air saturated with water vapor is exposed to cold windshields, the
water vapor condenses on the inside of the windshield--freezes if the
windshield's cold enough. When it's cold, it doesn't take much to
saturate the air with water vapor; 2 or 3 humans breathing normally in
an enclosed car will do that. I've seen this happen many times, but
then I live in Michigan, where it's usually humid and it's cold ~5
months of the year.

Ice on the *outside* of the windshield isn't affected by the moisture
content of the air coming from the defroster, just the warmth. You
still don't want moist air blowing against a cold windshield because
you'll get fog or ice forming on the windshield. Does this make sense
to you now?

 

Read the reply - did I say ice? No, I said humidity on the inside of the
window. Do you get ice forming on the inside of your windshield normally?
Think before you reply next time.

 

It makes sense that some folks have forgotten to define their terms.
AC on during defrost does NOT defrost the windshield more quickly! IT
TAKES LONGER.
Your talking about FOG, which is different than DEFROSTING. To say
that AC on
during defrost is quicker, is WRONG.

Xin

 

No, what you said was this:

"No there isn't a way to shut it off. The AC comes on to dehumidify
the
window area, thus clearing it more quickly."

No mention was made as to what side of the window you were referring
to, nor as to what "clearing it more quickly" was referring to.

I am just trying to make the point that some people are playing fast
and lose with some terms here, and some readers might get the
impression that AC defrosts the windsheild more quickly. It doesn't.
It actually slows it down, hence the desire of some to get rid of this
"feature". AC does work great with DEFOGGING, and I and many others
have survived thus far by turning on the AC WHEN WE NEED TO, BY
ACTUALLY USING THE AC SWITCH.

Xin

 

If the cabin is cold enough to form frost inside the windshield, the A/C
does not come on.

 

No, the A/C won't run, but the AC compressor will run when the
defroster is turned on.

 

The ECU monitors the input from the thermistor on the A/C evaporator to
prevent frosting of the evap. core surface. At start-up, if the temp. is below
set threshold, usually around 32 degrees, the ECU does not send ground signal
to the A/C relay, which means the compressor is not activated.

 

can you not just push the A/C button as I can in my 2004 Elantra GT and turn
it off in the defrost position???

 

The thermometer is ON the evaporator, which is loacted INSIDE the cabin.
It does not measure ambient temperature.