windshield condensation

rickselevation · October 7, 2021

If owned a 2015,2018, and now a 2021 Sierra, my wife has a 2018 Acadia, what is the deal with the front windshield collecting condensation on the outside, inline with the inside defrost vents it will happen at 70 degrees and damp outside ?? happened on all 4 vehicles . Anyone else have this issue, or an idea to resolve it.

Adamace1 · October 8, 2021

Are you talking about when your are driving? Is so some of the ac/ heat leaks through the defrost vents and will change the temperature of your windshield and make condensate more likely.

The only way to resolve it would be to turn the temperature on your climate controls higher so that air is warmer than the outside air.

Edited October 8, 2021 by Adamace1

redwngr · October 8, 2021

Anytime you make a surface colder than the dew point of the air passing across it air there will be condensation.

(that's how de-humidifiers work, and is the reason AC units create condensate )

'Here' we sometimes get conditions that can do that to the outside of a windshield -- but not very often.

Sometimes changing HVAC settings can help.

Sometimes it is necessary to resort to an occasional cycle of the wipers.

Phantom 4D · October 8, 2021

12 hours ago, redwngr said:

Anytime you make a surface colder than the dew point of the air passing across it air there will be condensation.

(that's how de-humidifiers work, and is the reason AC units create condensate )

'Here' we sometimes get conditions that can do that to the outside of a windshield -- but not very often.

Sometimes changing HVAC settings can help.

Sometimes it is necessary to resort to an occasional cycle of the wipers.