Cabin pressure

[Darko-Mk]

Hi All,

Not exactly something that could be fixed, I guess, just exchanging experiences.

There is this strange cabin pressure that is sometimes so annoying with only the front windows rolled down (halfway or all the way).
I would expect this to happen with the rear windows rolled down, but not with the fronts.

Any thoughts as to why this might happen?
Is it the car geometry or something else? Or perhaps this is something only my wife and I are noticing

Cheers!

[Macdemon]

At what sort of speeds does problem manifest itself?

[Ootohere]

@Darko-Mk What happens, are things / passengers sucked out the car or stuff sucked in, and as @Macdemonasks, at what speed ,

and at what altitude please ?

[Darko-Mk]

I would say it happens at speeds from 40 to 70 km/h (25 to 45 mph).

However, I don't think the altitude has anything to do with it, as I have noticed it on different places (therefore different altitudes).

"are things / passengers sucked out the car or stuff sucked in" - just weird feeling in the ears. I have felt it when the rear windows are opened, but I would say that is usual since it has happened in every car I have been in.
But never when only the front windows are rolled down.

[Ootohere]

No idea then, but good that the answer is just to drop the rear windows a bit if the fronts are open. 

 

Looking forward to hearing from others with the same car as you trying it in theirs or sharing any experiences already. 

[Exkiwi]

Turn the aircon on and keep the windows closed. Open windows put fuel consumption up and yes aircon might do as well but not as much. We run aircon at 22C year round 24/7 365

[gumdrop]

Is this the phenomenon where dust and empty plastic bags float about in the back of the car as in a vacuum?

My boys used to love this effect that we had in some cars I owned.

 

[J.R.]

31 minutes ago, gumdrop said:

Is this the phenomenon where dust and empty plastic bags float about in the back of the car as in a vacuum?

 

 

Do you have an anti-gravity machine?

9 hours ago, e-Roottoot said:

@Darko-Mk What happens, are things / passengers sucked out the car or stuff sucked in, and as @Macdemonasks, at what speed ,

and at what altitude please ?

And do the oxygen masks drop down?

[Ootohere]

If i had AC set at 22*oC i would need iced drinks and cold towels.

 

I seldom put the cars heating to 18*oC in the coldest of weather.  

[EnterName]

23 hours ago, Darko-Mk said:

Hi All,

Not exactly something that could be fixed, I guess, just exchanging experiences.

There is this strange cabin pressure that is sometimes so annoying with only the front windows rolled down (halfway or all the way).
I would expect this to happen with the rear windows rolled down, but not with the fronts.

Any thoughts as to why this might happen?
Is it the car geometry or something else? Or perhaps this is something only my wife and I are noticing

Cheers!

I've noticed this too. I think it's a weird air pressure that builds and has nowhere to go. Opening the rear windows a bit seems to solve the problem.

That was the best thing about having a sunroof (about 20-odd years ago). I could pop it open on tilt, and it would draw air through the car really well, without much buffeting or weird pressure build-up.

[gumdrop]

1 hour ago, J.R. said:

 

Do you have an anti-gravity machine?

And do the oxygen masks drop down?

No, it is some kind of venturi effect where fast moving air outside the car (with partially open windows) produces a vaccuum inside the car.

Mr Dyson loves the effect.

Edited 29 August, 2021 by gumdrop

[J.R.]

Pressure drop is the term you were looking for, like an airplane wing or an aerofoil.

 

Caterhams and Westfields with a full windscreen would all exhibit this effect at speed, hats would levitate no matter how tightly they were scrunched on, also anything loose between driver & passenger, on their laps or in the boot box, 99 times out of 100 they would disappear in a blink of an eye be invisible in the rear view mirrow and several seconds later re-appear where they took off from, it was like they were beamed up & beamed back down again by Captain Kirk.

[Exkiwi]

6 hours ago, e-Roottoot said:

If i had AC set at 22*oC i would need iced drinks and cold towels.

 

I seldom put the cars heating to 18*oC in the coldest of weather.  

Well its the last day of winter here today and temp is going to be 26C   In 4 months it will be 30 + nearly every day.  Lovely for my arthritic old bones.

[Seasider]

I've noticed the effect with the front windows down of an unpleasant feeling in the ears.   Can happen at low or high speed, so not directly speed related.  May be a combination of effects, vehicle speed, wind speed and direction, how far windows are down and whether they are down the same amount, even possibly effects of reflection of wind or sound waves from buildings.

[gumdrop]

https://jalopnik.com/why-do-slightly-opened-car-windows-make-that-awful-soun-1447498738

[skoda1982]

This happened in all athe skoda cars I've had when  the rear  windows open 

[Darko-Mk]

Seasider perfectly explained the feeling.

@skoda1982: I think it happens in all cars when the rear windows are opened, and I think only when the rear windows are opened.

[DRW]

We used to get an effect in our Rapid which caused a mild but annoying throbbing in our ears.  Unable to track it down.  Have now traded it in for a new 1.5 Kamiq and haven't had any trouble at all.  Some theories on the Rapid forum were adjustment of the tailgate, the parcel shelf vibrating, tyres......  Worth having a look at the Rapid owners' forum.   Dealer claimed they'd never come across it.