The Passive Car Cabin Cooler

[Airbrush]

Why does this never get invented? The problem is car cabins can get VERY hot when parked under the sun. The temperature inside a car can get so high it will kill any babies or pets accidentally left inside the car. Even an adult will die inside a closed car in the hot sun, if they are unconscious or disabled. Also, it is very uncomfortable to start a very hot car.

 

All it takes is intake fans in the floor of the car and exhaust fans in the ceiling, and the fans are powered by solar cells on the roof of the car. This would ensure that it could never get hotter inside the car than it is UNDER the car, in the shade, (because that is where the air intake is). Nobody can die of heat inside such a car.

 

This could be enhanced by a swamp cooling system to make the air intake from the floor even cooler by passing through a water-cooling system. Why does this never get invented?

Edited June 14, 2017 by Airbrush

[Manticore]

Because the car manufacturers don't give a shit as long as they've got your money.

[Bender]

The potential gain does not outweigh the additional cost.

 

In this case, nobody would buy an ugly, expensive car with solar panels and fans in the roof, because leaving a baby in the car "will surely never happen to them" anyway.

 

To put in some figures:

On average, 38 children die this way every year in the US.

In 2015, 938 children died in motor vehicle accidents in the US.

 

So it makes sense to put 25 times more effort into preventing the second category.

 

But if it really bothers you, nothing prevents you from putting a fan in you roof and installing a solar panel on top. It isn't even that difficult to do yourself. I'm not really sure that it would be 100% effective, though. The air can only get as cold as the surrounding air, possibly heated by blistering tarmac on a parking lot. Still a considerable improvement, obviously, but a child left for hours under those conditions could still die.

Because the car manufacturers don't give a shit as long as they've got your money.

I don't think this is entirely fair. Why would they sell a car that nobody will buy?

 

 

An afterthought: wouldn't such a system encourage parents to knowingly leave their children in the car "only for a minute"?

Edited June 14, 2017 by Bender

[DrKrettin]

The potential gain does not outweigh the additional cost.

 

In this case, nobody would buy an ugly, expensive car with solar panels and fans in the roof, because leaving a baby in the car "will surely never happen to them" anyway.

 

To put in some figures:

On average, 38 children die this way every year in the US.

In 2015, 938 children died in motor vehicle accidents in the US.

 

So it makes sense to put 25 times more effort into preventing the second category.

 

But if it really bothers you, nothing prevents you from putting a fan in you roof and installing a solar panel on top. It isn't even that difficult to do yourself. I'm not really sure that it would be 100% effective, though. The air can only get as cold as the surrounding air, possibly heated by blistering tarmac on a parking lot. Still a considerable improvement, obviously, but a child left for hours under those conditions could still die.

I don't think this is entirely fair. Why would they sell a car that nobody will buy?

 

 

An afterthought: wouldn't such a system encourage parents to knowingly leave their children in the car "only for a minute"?

 

Interesting stats. Totally off-topic, but the first link is written by a "Dr. Richard Osbaldiston, Ph.D.". This is tautology - I thought the convention was that you were either Dr Z. Krettin or Z. Krettin PhD, but not both. Or is the convention different in the USA? (like everything else)

[studiot]

 

but the first link is written by a "Dr. Richard Osbaldiston, Ph.D.". This is tautology - I thought the convention was that you were either Dr Z. Krettin or Z. Krettin PhD, but not both. Or is the convention different in the USA? (like everything else)

 

You can be a Dr. with or without a Ph.D. simply by being a medical doctor, anywhere.

[Strange]

An afterthought: wouldn't such a system encourage parents to knowingly leave their children in the car "only for a minute"?

 

 

Good point.

[Phi for All]

Obviously in these times nobody should be leaving living things alone in parked cars for any amount of time. And I think they've taken care of the main problem, entering your scorching hot car, with remote car starters. You can start your engine and air conditioning (or heater) from the home or office, before you get in. It's a retrofit system most car toy stores have.

 

 

Totally off-topic, but the first link is written by a "Dr. Richard Osbaldiston, Ph.D.". This is tautology - I thought the convention was that you were either Dr Z. Krettin or Z. Krettin PhD, but not both. Or is the convention different in the USA? (like everything else)

 

Perhaps Osbaldiston works for the Department of Redundancy Department?

[Endy0816]

For evaporative coolers, would have to consider the effect that higher humidity levels would have.

Edited June 14, 2017 by Endy0816

[DrKrettin]

You can start your engine and air conditioning (or heater) from the home or office, before you get in.

 

Ignoring the issue of global warming, would this not be illegal, if your car is parked on a public road with the engine running and you are not there? I'm fairly sure that this is the case in Europe.

[Airbrush]

The potential gain does not outweigh the additional cost.

 

In this case, nobody would buy an ugly, expensive car with solar panels and fans in the roof, because leaving a baby in the car "will surely never happen to them" anyway.

 

The air can only get as cold as the surrounding air, possibly heated by blistering tarmac on a parking lot. Still a considerable improvement, obviously, but a child left for hours under those conditions could still die.

I don't think this is entirely fair. Why would they sell a car that nobody will buy?

 

An afterthought: wouldn't such a system encourage parents to knowingly leave their children in the car "only for a minute"?

 

How much does a few fans in the ceiling and floor, and solar panels on the roof, of a car really cost? It may be a very cheap addition.

 

"Ugly expensive solar panels and fans"? The system would be unnoticeable.

 

The air inside the car could only get as cool as the air in the shade under the car. A simple swamp cooling system could lower the temperature even more.

 

Why not leave anything or anyone in the car if there is air coming in through the floor and hot air expelled through the roof, and the temperature could not go above the temperature of the air in the shade under the car? I could take a nap inside my car on a 100 degree day with the windows closed.

 

Cars should not be death traps waiting for a child or pet victim. Also it would never feel so burning hot inside your car on a hot day.

Edited June 14, 2017 by Airbrush

[zapatos]

How much does a few fans in the ceiling and floor, and solar panels on the roof, of a car really cost? It may be a very cheap addition.

 

"Ugly expensive solar panels and fans"? The system would be unnoticeable.

 

The air inside the car could only get as cool as the air in the shade under the car. A simple swamp cooling system could lower the temperature even more.

 

Why not leave anything or anyone in the car if there is air coming in through the floor and hot air expelled through the roof, and the temperature could not go above the temperature of the air in the shade under the car? I could take a nap inside my car on a 100 degree day with the windows closed.

 

Cars should not be death traps waiting for a child or pet victim. Also it would never feel so burning hot inside your car on a hot day.

 

I'm not so sure that is true. Even when I leave my windows open the inside of the car is much hotter than it is outside. I think it would take quite a fan to cool down everything inside the car that is heating up by being in the sun.

[DrP]

Would it even need solar panels and fans? Would not a simple hole in the top and bottom work to get a flow of air passing though. Of course you would need to be able to close off the holes in bad weather.

 

My car was so hot the other night after work... For the first time in about a year I pushed the big red button and reached for the shades. 8-)

[Phi for All]

Ignoring the issue of global warming, would this not be illegal, if your car is parked on a public road with the engine running and you are not there? I'm fairly sure that this is the case in Europe.

 

I don't know the specifics of the device. It wouldn't be the first time the US allowed the sale of something that was illegal to actually operate (fireworks are one example).

[Airbrush]

Would it even need solar panels and fans? Would not a simple hole in the top and bottom work to get a flow of air passing though. Of course you would need to be able to close off the holes in bad weather.

 

Exactly.

 

The ceiling holes would avoid rain entry by a simple baffled intake. Just openings in the floor and ceiling would be enough to dramatically lower the temperature inside the car (and accumulation of CO2). Then enhance the air flow a bit with small fans powered by solar panels on the roof. And if you are wealthy, your passive cooling system could even have a swamp cooler component.

Edited June 14, 2017 by Airbrush

[Externet]

It has been invented; it is in the aftermarket. I have one. It is wimpy but works... barely. A beefier one or several should do well.

 

----> https://duckduckgo.com/?q=solar+car+ventilation+fan&t=canonical&iax=1&ia=images

 

Hangs on the edge of the glass, Has its drawbacks as for lazy people to remove them when they want fully shut/open windows. Improve it and put it on the market.

[John Cuthber]

Fundamentally, if people are too stupid to leave the window open a bit, they are not going to understand the advantage of having a fan or two; so they won't buy it.

 

Exactly.

 

The ceiling holes would avoid rain entry by a simple baffled intake.

Baffles will struggle a bit at 70 MPH.

[Airbrush]

It has been invented; it is in the aftermarket. I have one. It is wimpy but works... barely. A beefier one or several should do well.

 

I also had one in my car window, but it is very weak. A factory installed system, with ceiling exhaust vent and floor intake vents, could be a magnitude more robust at moving air through the car. There could also be a retrofit kit, which requires cutting a 3" diameter hole in the roof, with baffle facing rear so as not to catch rain or act as an air scoop (like a p-51) while driving at 60mph. And also cutting a couple of holes in the floor for intake vents. A swamp cooler could be attached to the undercarriage and simply route the air intake through a radiator to cool the air before it enters the car. The water reservoir could be filled through the trunk. When the water supply is used up the cooler still works, just not as effectively.

Edited June 15, 2017 by Airbrush

[DrP]

Also, with regard to 'leaving the windows open' - that could be viewed as a security risk - even if left open a fraction that can make it much easier to break into a car..... Although saying that, if someone REALLY want's to get into your car they will, regardless of whether the windows are open or not, but there is no point in making it easier for them.

[Externet]

Instead of perforating, modifying a roof and ceiling and baffles and rain and reupholstering and...

A solar panel by the package tray under the rear windshield -or front- can power a duct fan evacuating hot air into the trunk which is usually implemented with flap vent valves that allow closing the rear trunk without increasing pressure.

Other places in a vehicle are suitable also to discharge hot air.

Allowing exterior air to get in has to be evaluated by checking at which position the levers and controls for HVAC leave a passage open.

 

Vehicles have useable disguised vents at several places ----> https://duckduckgo.com/?q=c+pillar+vent+&t=canonical&iax=1&ia=images

[Bender]

Why not just use the ventilation system already present in the car and add a smaller fan connected to solar panels?

Edited June 15, 2017 by Bender

[Airbrush]

Why not just use the ventilation system already present in the car and add a smaller fan connected to solar panels?

 

That will work also. But the MOST effective design for moving air through the car would be an exhaust vent at the highest point, the ceiling, and intake vents at the lowest points, beneath the front and rear seats.

[Bender]

 

That will work also. But the MOST effective design for moving air through the car would be an exhaust vent at the highest point, the ceiling, and intake vents at the lowest points, beneath the front and rear seats.

Why? In a lot of parking lots, I expect the air to be hottest near the grond. I can't really find proper data apart from the fact that above 1 foot all air has more or less the same temperature.

[Externet]

Tampering with the ventilation system or its electricals can trigger warranty issues, or failures, for those who care. And takes studying the service manual for each vehicle to disassembly , modify and reassembly correctly.

Adding an independent solar powered ventilation may have advantages as reversability.

[Bender]

Tampering with the ventilation system or its electricals can trigger warranty issues, or failures, for those who care. And takes studying the service manual for each vehicle to disassembly , modify and reassembly correctly.

Adding an independent solar powered ventilation may have advantages as reversability.

It was a suggestion for what could be a simple solution at car manufactury level.

[Airbrush]

Why? In a lot of parking lots, I expect the air to be hottest near the grond. I can't really find proper data apart from the fact that above 1 foot all air has more or less the same temperature.

 

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

 

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.

Edited June 25, 2017 by Airbrush