Air circulation

[Kat_]

Have you considered installing something like the Fantastic Fan or some kind of rooftop AC on your car? 
My car is too hot and stuffy at night, especially in humid weather.  While rolling down the window helps I’m not always in the environment that keeping my windows rolled down when I sleep is a good idea.

 

[dawnann7]

I have thought of it and would be interesting to hear from those who have tried it.

 

[wypoon]

I would be very wary of installing a RV-style roof fan on a *car*:

i. Will make selling the car much more difficult. Unlike a campervan or trailer, this is not something that *car* buyers are looking for, or find beneficial.

ii. Much increased road noise. I've a moon-roof on my SUV, and it's nuisance LOUD.

iii. Decreased fuel economy. These RV-style fans protrude quite a bit above the roof and will significantly degrade the aerodynamics of a car (an RV or tall van, no so significant because they're NOT aerodynamic to begin with, but cars are). I had roof racks installed on my SUV, and saw an immediate dip in highway MPG.

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I would also stay away from the solar gimmicks that mount on the window (they have very poor reviews and solar doesn't work at night anyway).

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Instead, I recommend buying the factory service manual (not owner's manual) for your car (try Ebay) and then wire up the built-in fan (by locating the fan relay harness) with a bypass switch to your car's battery. With the fan set at its LOWEST, it'll be quiet and should not drain your battery down if you drive everyday to recharge it.

 

[deadwood]

Air circulation is everything. I would try to figure out some way to have a fan going in the car to get the most ventilation as possible. I don't see putting a RV fan in the roof of a car either but setting up some sort of a fan and having the windows cracked would make a huge difference. You could also put on some of those plastic rain guards over the windows to keep any rain out and be able to crack the windows without anyone really being able to see they are open an inch.

 

[DannyB1954]

You could have a sun roof installed and fasten a 12 volt fan in place. Walmart sells a 9" 12 volt fan for $15. Put it on low and it should not drain the car battery. Or install a second battery to be safe.

 

[Dingfelder]

They do have fans made specifically to fit in the cracked window of a car.

 

[Jacksonricher]

What about mounting one or two small fans behind the back seats on the speaker panel and get air from the trunk???

Or get a row of computer fans and have them in a slighly rolled down window? Then crack open another for circulation??

 

[GotOldEarly]

I have not tested long term yet but I built a very inexpensive exhaust system using 12 volt computer fans.  Power draw is minimal (0.38 amps max @ highest setting) via single USB connection.  The frame for this is made of 1/4 inch plywood.  The fans come with their own speed control pre-wired.  They can be run @ off, low, med, or high speed and are extremely quite at all speeds.  Luckily, my 4Runners side rear windows are nearly square and thus the wood cutting was greatly simplified.  A very small step with much still to do to get the 4Runnuer live-in ready.  Not sure if the attached picture will make it but attaching it and hoping. I'm such a newbie at this.

 

[RowanFae]

I can't answer your question, about roof fans. I have no knowledge or experience.

Hmm, I have seen people add the 'gutter?' strips (I don't know what they are called) over their windows to prevent rain and then using screens attached by magnets so they can leave their window open and having rechargeable fans in the vehicle for airflow.

ETA: I looked it up, it is called a "Wind Deflector rain deflector."