For a properly functioning auto, what's the quickest way to defog the windshield? There are lots of air control options - hot vs. cold air, exterior vs. recirculated air - but which are the most effective (assuming the auto is functioning correctly)?
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It will depend on your car, the outdoors humidity, the air temperature and the engine temperature. As an example, for me on a cold icy morning starting with a cold engine:
- aircon on
- fan on low
- use external air, not recirculator!
- front windscreen demister (covers wiper rest area)
- rev engine until at working temp
- then put fan on high
But in high humidity areas in the summer I would use:
- aircon on
- fan on high
- use recirculator
Rory Alsop
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Hot air from the exterior with your a/c on is the quickest. Though in general having the a/c on is the most important piece, as it removes moisture from the air.
Scott Hillson
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My old Fiat Marea Weekend had instructions for defogging the windshield on the inside of the driver's visor:
- Turn the blower on max
- Turn the heat on max
- Turn the recirculation off
- Put down the visors
I was wondering about that last bit, so I've asked a follow-up: