How To Cool Down Your Car Without A/C

There is IR paint/coating for metal roofing in classic barn red and other darkish colors. It doesn't have to be white/light. I have put roofing samples out in the sun, and the temperature difference between the IR coatings and regular coatings is remarkable.

An excerpt from
http://www.coolmetalroofing.org/elements/uploads/casestudies/TMI_CaseStudy_25.pdf

In general, dark colors absorb most of the visible light striking the surface while lighter colors reflect most of that solar energy. This would suggest that color is an indication of how much solar visible energy will be reflected. The amount of infrared energy that is reflected is often a function of the color as well, but recently new pigment technology has been introduced to change that assumption. New IR reflective pigments in paint systems allow for darker colors to actually reflect more total solar energy. [end of quote]

The above study also contains a graph showing how much of the solar spectrum is in the infrared.

For the record, since I couldn't get a light green 2011, I wanted Blizzard Pearl, but all the ones coming in at the dealership had leather and other high-end options we didn't want.

 

Back in the 90's a buddy of mine had an IROC, nice car but no A/C. He would get in the hot car and drive off without opening the windows. After boiling for about 5 minutes, he would open the windows, and I swear, it FELT like A/C.
In this example, the extra effort will make you feel comfortable once you sit down and drive away. I would just stick with A/C

 

Please correct me if I am misunderstanding, but the IR paints claim to fame seems to be high emissivity. The reflectance results mirror what is expected based on their color.

 

Most things have an emissivity around 0.95 (on a scale of 0 - 1). Not much higher to go.

Link is broken.

While it might be possible to create a dark IR paint that reflects more Solar energy than an IR absorbing light color, I find it hard to believe that you can make one that reflects more than a IR reflecting light color.

 

Sorry, I didn't test the link after I posted. I replaced it, but it still acts broken. After clicking it, click "Case Studies" then "Cool Metal Roofing - An Emerging Hot Topic" to get to the study.

I, too, doubt that a dark color with IR (infrared reflecting) pigment is cooler than a light color, but it is more cool than the same darker color without the IR pigment. In other words, there's a way to improve the heat-absorption situation with darker colors. Wouldn't it be great to have a Barcelona Red car that was cool to the touch (that is, ambient temperature) after sitting in the sun?

 

If you want to cool down your car without A/C do this:

Move to the northwest along the Pacific Ocean.....

A/C is not needed.....

The land of 9 months of winter and 3 months of spring...

alfon

 

Your link has a trailing colon in it that breaks it. I removed it from my quote here.

 

Actually long ago I put in white seat covers and draped a white towel over the dash. I wanted white because I thought it would look cool. Temperature inside went down by 10 F. But since I worked in warehouse they didn't stay white long.

 

I guess that would do ok for an exchange of air. Recently I've been opening the door, putting foot on brake without getting in car, turning on power and then just stepping aside for a very short while (15 seconds) as AC gets going. Only on the hottest of hot days, though.

 

Even on 100 degree days I find the combination of the sun shield, tinted windows and a short period of time where the "windows are completely down works fine for cooling the interior.

If you can cool the interior to ambient temperature before starting the AC then you'll reduce the initial mpg hit imposed by the AC compressor. I noticed a 10mpg drop when the AC is, working hard upon activation and the interior is much hotter thank your desired AC setting. I then tested the system when the interior temp wash closer to the desired setting and the hit was only 1 mpg.

 

Whatever the science of it, if I open and and close the door that many times on a hot day, I've worked up my body heat so much as to cancel the effect of this scheme.