Solar Powered Ventilation?

[swng]

I have searched the forum for "Solar Powered Ventilation" and found no result. I presume that the device that I am going to describe has not been discussed in depth.
I have come across a flier which mentioned a device that looks like a ventilation fan to be clipped onto the window. It is powered by the sun and is to be attached onto the top of the car's closed window like a rider (but please read on) whilst the car is parked under the sun. The fan is supposed to keep the car ventilated and thus relatively cool. In theory this should reduce the workload of the AC when the car is driven again after parking and hence help save fuel. It costs $10 Canadian when on sale a few days ago. It is now sold for its regular price of $20.
I have to park under the sun very often and am tempted to give that thing a try because I think it may pay for itself by saving fuel. Just don't know if other members have any experience with this kind of devices. Apart from whether it is effective, my concern is whether the device, which I think will necessarily cause the window to leave a narrow opening whilst it is clipped there, will significantly compromise the car's overall security (from theft).
Can such a device be considered a true fuel saving device and should I buy it or dismiss it? Any comments welcome, please!

[GasSavers_maximilian]

I've never tried one myself, but a few people said they didn't work well in a roof mounted solar ventilator thread I started a while ago.

[theholycow]

I bought one. It was absolutely worthless. It didn't deliver on its promises. The car was hot, and the cheesy plastic stuff didn't fit the window well at all, leaving it just as insecure as if I merely left the window open.

[Jay2TheRescue]

I have one. I bought it at a thrift store for $1. Yes the truck is still hot, but I don't believe its as hot as if it sat with the windows up. One thing I noticed though, the fan doesn't run unless it gets direct sun. If you don't put it on the "sunny" side of the car, it doesn't work at all.

I don't think it was a total waste of money, I think its worth at least the $1 I paid for it.

-Jay

[swng]

Thank you ladies and gentlemen, including those who will comment after this post! You have once again proved that this is a really helpful and welcoming site .
I dare not put one on the roof. It rains here . If the dollar shops have them, may be I will buy 1/2 dozen for just $6 and put them on all windows to increase the ventilating power, or may be even more so that they leave no opening anywhere on any window. But seriously, I appreciate the useful advice . I am not going to touch them @ $20 each.

[GasSavers_maximilian]

They make watertight roof mounted solar vents for RVs (and houses), but you have to cut a hole in the roof (hole for RV ones can be smallish, though). I also haven't found one that'd be suitable for a car. Gave up on it so I stopped looking.

[bobc455]

Just a question for those who "tried and failed" -

In addition to the window fan, did you also open another window to get air cross-flow? I would imagine the product would be completely useless if you try to exhaust hot air without providing an inlet for cooler air (most likely on the opposite side of the vehicle).

-Bob C.

[theholycow]

Cross-ventilation wasn't the issue, I made sure to provide for it; the thing just didn't run well, even in direct sunlight.

[GasSavers_Scott]

I kid you not, I was planning on buying one of those window slit solar fans this month. I have a black car and its Baltimore and it gets hot. If I can I leave the windows and the sun roof cracked a quater inch if Im lucky. If you live on the East Coast, you will get humidity and heat in the 90's and then pause for a hour or two for showers, so you have to keep an eye out for the weather so you dont get your car washed from the inside out.

What I have been looking for is those 2 inch tinted platic forms that stick to your upper window seal of your door, that way you can leave the windows down an inch and get flow through. They also function during those summer rain storms while driving to get the steam out of the car.

[theholycow]

Originally Posted by Scott

What I have been looking for is those 2 inch tinted platic forms that stick to your upper window seal of your door, that way you can leave the windows down an inch and get flow through. They also function during those summer rain storms while driving to get the steam out of the car.

The most common brand name is VentVisor, if you're having difficulty searching.