The Passive Car Cabin Cooler

[John Cuthber]

Web sites about gliding cite large tarmac car parks as good candidates for places where hot air will be rising.

Black stuff isn't typically cool in sunshine.

So, when you first park, you will be pulling in unusually hot air.

[Bender]

The air is hottest in direct sunshine. Under the car is shade. Much cooler air in the shade.

I'm going to need a source for this one. Air moves around between shadowy and sunny regions, and the limited data I could find on the issue suggested that only the air very close to a hot surface is actually warmer.

 

However, you are right, because as soon as the cool air under the car is sucked up into the car, that will quickly pull the hot air, that was baking in the hot sun, right under and into the car. So that is why a solar powered swamp cooling system, passing air through a radiator device would help. Maybe also a "skirt" around the bottom of the car, that unrolls when the passive system is working, but rolls back up when the car is driven. That would restrict the free flow of air from the sunshine to under the car and allow the air under the car to cool off more.

How would that skirt work? Where would the air come from? There isn't that much air underneath a car, and even if you could suck it completely vacuum it would run out very quickly. (on top of the fact that that air isn't actually cooler.) Edited June 25, 2017 by Bender

[Airbrush]

Web sites about gliding cite large tarmac car parks as good candidates for places where hot air will be rising.

Black stuff isn't typically cool in sunshine.

So, when you first park, you will be pulling in unusually hot air.

 

That is only if you park after the asphalt is very hot. If the car was parked long enough, especially overnight, the air under the car will be cooler because it was in the shade. But that is not good enough, because in the heat of the day the air under the car will be used up in a few minutes, so surrounding hot air will get sucked under the car. That is why I propose retractable "skirts" around the car that interferes a little with hot air getting under the car.

I'm going to need a source for this one. Air moves around between shadowy and sunny regions, and the limited data I could find on the issue suggested that only the air very close to a hot surface is actually warmer.

 

How would that skirt work? Where would the air come from? There isn't that much air underneath a car, and even if you could suck it completely vacuum it would run out very quickly. (on top of the fact that that air isn't actually cooler.)

 

The skirt could automatically unwind, like a window blind, but it does not create a perfect seal preventing air from getting under the car, just slows air flow down so the air under the car has time to cool for a while, before it gets sucked up into the swamp cooler before entering the car under the seats. All the while hot air is expelled through the ceiling vent.

Edited June 25, 2017 by Airbrush

[Bender]

The skirt could automatically unwind, like a window blind, but it does not create a perfect seal preventing air from getting under the car, just slows air flow down so the air under the car has time to cool for a while, before it gets sucked up into the swamp cooler before entering the car under the seats. All the while hot air is expelled through the ceiling vent.

Why would the air cool down under the car?

Why would it meaningfully slow down the air flow? It just means you either have a lower air flow to ventilate your car, or you need a bigger fan and a bigger solar panel to keep the air flowing.

[John Cuthber]

To be fair, any air flow is likely to help cool the car.

However, from my point of view I would have two holes that let the mud, rain and noise in all year so the car didn't overheat on the few days of the year when we get much sunshine.

 

It's not as if the air temp is the only problem with leaving pets or kids in the car.

[Endy0816]

Too humid for a swamp cooler to work well :'(

 

They are a cool technology(pun unintended) more suitable for dry climates though.

Edited June 25, 2017 by Endy0816

[John Cuthber]

Swam coolers- or, as they are sometimes called, culture vessels.
https://en.wikipedia.org/wiki/Legionella

[Airbrush]

Ok, I give up. I'm no engineer or chemist. My areas of experience are accounting and art. Maybe a swamp cooler that uses some other liquid than water?

 

Cars are everywhere on Earth now. The person who figures out the passive car cabin cooler retrofit will be a great international hero. All that is required is rendering a car impossible to kill a normal healthy person, baby, or pet, on the average hot summer day. It does not need to be COOL inside, it only needs to be NOT deadly. And what the heck, Billions of people could even take naps in their car on their lunch break, when the weather is 96 degrees in the shade.

 

I give up on this problem, and I hope someone comes up some day with a great idea and design, an inexpensive fix to the problem of deadly heat exhaustion inside cars.

Edited June 26, 2017 by Airbrush

[John Cuthber]

...

The person who figures out the passive car cabin cooler retrofit will be a great international hero.

...

Open the windows. Maybe put some insect screens over them.

Apparently, I am now an international hero.

 

Should I add it to my signature?

[Airbrush]

Open the windows. Maybe put some insect screens over them.

Apparently, I am now an international hero.

 

Should I add it to my signature?

 

No, you cannot just open the windows, because then you are not secure. If I am taking a nap in my car on my lunch break, or if someone is homeless or camping and sleeping in their car at night, I would rather the windows be closed so a thief will not be able to enter my car and steal from me or hurt me.

Edited June 26, 2017 by Airbrush

[Bender]

 

No, you cannot just open the windows, because then you are not secure. If I am taking a nap in my car on my lunch break, or if someone is homeless or camping and sleeping in their car at night, I would rather the windows be closed so a thief will not be able to enter my car and steal from me or hurt me.

Most stolen cars have their windows closed at the time of theft.

[zapatos]

 

No, you cannot just open the windows, because then you are not secure. If I am taking a nap in my car on my lunch break, or if someone is homeless or camping and sleeping in their car at night, I would rather the windows be closed so a thief will not be able to enter my car and steal from me or hurt me.

 

If you are napping in your car at lunch with the windows rolled up and it is hot outside, I don't think your car cooler is going to keep you comfortable enough to sleep.

At night you can keep the windows rolled up anyway as it shouldn't get hot enough to kill anyone inside.

[John Cuthber]

 

No, you cannot just open the windows, because then you are not secure. If I am taking a nap in my car on my lunch break, or if someone is homeless or camping and sleeping in their car at night, I would rather the windows be closed so a thief will not be able to enter my car and steal from me or hurt me.

How hot is it most nights?

[Airbrush]

How hot is it most nights?

 

Only when nights are very cold would you be comfortable sleeping in your car with no ventilation at all. On most nights, you would prefer fresh air circulating through your car, and you would usually not leave your windows open while you sleep, unless you are parked in a very secure place.

 

I have an SUV with a moon roof which I leave open 1/2 inch always, except when it looks like rain, and my 2 rear windows open about 1/2 inch. That helps in hot weather, but not enough.

Most stolen cars have their windows closed at the time of theft.

 

It takes a dedicated criminal to break a car window to enter and steal the car or anything inside the car. An open window is an invitation to any opportunist. And close to 100% of stolen cars don't have someone sleeping inside. Thieves are usually avoiding contact with people.

Edited June 27, 2017 by Airbrush