There are some people I know who would put up a sun shade behind their front windshield every time they park. These people insist that it helps to keep the interior of the car cooler on hot days. I don't believe sun shades make any difference at all.

So are there any studies done that sun shades help to keep the interior cooler? And if there is a difference, does any type of sun shades stand out as being more effective? (card-board, silver plastic, fans, fabric/mesh/net, ...)

Or conversely, any studies showing sun shades make no difference?

Thanks.

 

There are no studies I know of that say sunshades work expressly for cooling car interiors, and I would find any study that said that suspect at best. I put shades up every time I park for an extended period, but I don't put them up to cool the car. I put them up to save the dashboard from being destroyed. It just turned ugly here in Phoenix, and it's time for me to use the shades more than ever.

I suppose one could argue it cools interiors ever so slightly, in that by using shades, the sun is not hitting and heating the dashboard directly, but ambiently. But here in AZ, it's rather hard to tell the difference. =|

 

In the right conditions it can help, I think.

Where I work, there are a lot of places you can park partially under a tree. So I used to back my car in, so most of it is in the shade of the tree, and then put a sunshade up to keep out the rest.

It felt cooler, but I also roll down my windows with the key as I walk up, so who knows.

'Course, that was when the car was new and I wanted to protect the dash and all that.

Now it's two years old and I'm lazy.

 

Yes, they do keep it cooler, or another way to look at it is they make it heat up slower because they reflect the solar energy. In high school I had a black car with a black interior and no AC. The sunshade keep it much cooler but I grant you, they are cumbersome and a pain.

If the sun comes in other windows it will still heat up. Think of it this way on a 90+ degree day you see two parking spots, one in the shade and one in the sun, which one will have a more comfy temp in the car when you get back to it?

 

I fully understand that parking in the shade will keep the car cooler. But that is not what I was asking about. I am asking about when the car is parked in the open, under the sun. So given two identical cars, parked side-by-side in the sun, one has a sun shade and one without, would there be any difference in the interior temperature?

Protection against sun damage to the dash is a valid reason to use a sun shade.

 

[QUOTE=WhiteS2k,Jun 6 2006, 01:45 PM] So given two identical cars, parked side-by-side in the sun, one has a sun shade and one without, would there be any difference in the interior temperature?

 

Yes, I agree with everything you said in theory. But I have not seen anything that shows realistically (in a real world) that it makes any difference. All I can say is that I don't feel any difference getting into a hot car whether it has a sun shade or not. So I am looking for some study that someone has done.

 

Not everything requires a "study" to convince most people

I used sun shades religiously in my old car, both for lowered temperatures, as well as dashboard protection. Thankfully I park mostly indoors nowadays with the S2k, so I don't have to worry about sun damage or heat.

Think of it like this. Park two cars side by side, and put a sunshade in one of the windshields. After two hours, which dashboard will be cooler to the touch? The dash in the shade no doubt. Now, with one dash hotter than the other, can we come to the conclusion that the ambient temperature within said car will ALSO be hotter?

You will probably make the argument: "But what about the sun shade? Won't that be as hot as the dash?" Well, possibly, but only if the sunshade were made of the same material as the dash. Most sunshades today are made of some sort of reflective material (as has been mentioned already.) These shades do a better job of fending off the sun's rays (and subsequent radiant heat) than your dashboard does.

Do we still need a study?

 

I use a sunshade whenever I am parked in the sun for extended periods. One thing is for sure, depending on the angle of the sun, my black seats stay a heck of a lot cooler. I also have 20% tint on the other 3 windows.

 

It is an easy test if you want to do it yourself. If you have a sun shade, a car, and two temp gauges(one for outside temp and one for inside temp).

Anyways, I think the best thing to do is to get your windows tinted. I have 20% on my three windows and 50% on my windshield. All of the tint is the reflective kind(not the mirror tint, there is a difference). Since I havve got the tint my seats, steering wheel, and shift knob are never "hot" to the touch. Even in the three digit temps we get here in Central Oregon.