Independent lab test (me) says Auto-Cool can't work

Iamme

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Have you seen that commercial on tv where they show 2 identical cars parked side x side in the hot sun and they go on to say that the car without the Auto-Cool ventilator system got to 107 degrees in the car, while the car next to it, WITH the Auto-Cool had an interior temp of 75? And it only costs $14.95 and they even throw in a cup/change caddy?See that ad?

You believe the claim?

I couldn't believe it. Not after I have heard that a standard house window can let in something like 5000 btus of heat. While the Auto-Cool is only about twice the size of a pack of cigarettes and has this, what looks like, only a 2 inch fan or so inside of it?

So I went out to my car one day when the conditions were right, in July. It was sunny and 73 out. I had an alcohol thermometer on the front seat, not in the sun, and it said it was 96 in the car. And that was with the windows down some on each side of the car.

I then rigged up an 8 inch fan that I have, that is 75 watts. I put it in the passenger front window and cardboarded all the way around it so it HAD to draw outside air in through the car. I lowered the opposing front window about 1 1/2 inches. Turned on the fan on 'hi'. After the thermometer stablized after running the fan a long time (plugged into my cigarette lighter with an ac/dc converter)...care to guess what the temp inside the car came down to?...with the *8* inch fan?
 
Before I answer this...have any of you actually considered buying one of these? My older neighbor, who spies on me and who watched me experiment, got into an argument with the cronies down at the local cafe about this and he told them all about my experiment. His parting words to them were, "YOU go ahead and buy one then. If it works, *I'll* buy one." So far, none has returned saying they bought one.

I have a feeling that many people will send for one of these, then ask for their money back. And they will be out shipping and handling charges. I could be wrong about this, but that's my guess.

And have you noticed that in the bottom left hand corner of the ad, it says that "your results will vary". WILL...not MAY. Ha. They are even telling you. Ha.
 
Don't tell me, this has you bolting together something else made by the genius carpenter from the ice rink.
 
Just thinking said:
Gee ... I wonder how well it works when it's 85 in the shade.
Click to expand...

Well, like any ventilator system, I imagine it leaves the inside a little warmer than the 85 in the shade, instead of the 130 or so it would be with the windows rolled up tight.
 
Would it work, or won't it?

I looked for the smallest radial fan (not axial - not the proper flow direction, not crossflow - the animation did not support it) which was 45mm x 15 mm. Maximum airflow was 0.075 cubic meters per minute.

An average sedan has a cab area of about 1.5m x 1.8m x 1.0m = 2.7 m cubed. This is not including the seats, slope of the windscreen, etc, which would lessen the volume.

So now, 2.7 / 0.075 = 36 minutes. It would take the small fan 36 minutes to completely change the internal air in the cab.

A Stanford U study showed that a car parked in the sun could heat up an average of 40 degrees F in an hour, and 80% of it in half an hour. (=32 degrees F)

My conclusion is this -
The fan will slow down the rate the temperature rises, but not change the absolute temperature reached.

I conclude this because in approximately the same time, the fan manages to remove the air in the cab, but this does not take into account that the incoming cool air is simultaneously being heated by the sun. Also, the items in the cab are being heated directly by the sun, in which case, the air will then also be heated by contact and not only by radiation through the windows.

(as you can see, I had a lot of free time today.)

Mythbusters did an experiment with a black car and a white car and the respective cab temperatures in the afternoon were 135 degrees F and 126 degrees F.

So, my final answer is - your car temperature was 105 degrees F. Pray tell, what is the answer? :)
 
I find that those windshield covers, whether cardboard or silver foil, do about the best job. They don't keep the air inside the car from heating up, but they do keep the sun from directly heating the seats, steering wheel and most other things that you're liable to come in contact with.
 
I used to drive a mini-moke, with a vinyl roof but no side-curtains. The seat cushion is level with the side boxes.

At least once every summer I would jump up immediatly, after sitting down while wearing shorts.
 
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