OK physics guys - I got a car windshield sunshade - one side is gold and the other side is silver, is the car?

Question

cooler with the gold side facing the sun or with the silver side facing the sun?

Dan and Dr R and gemrtz - sound thinking

Tipper - would have agreed with you except at the end you said "black" and I strongly disagree with that.

edgeha - I was wondering about that....

johnand - NASA uses gold for what? ... u need a reason

Answer 1

I would say that as a general rule, it's not going to make much difference.

Gold reflects part of the solar radiation spectrum better than silver, silver reflects other parts of the spectrum better. Which part averages out better is anyone's guess.

However, any difference due to the reflection from the screen in the windshield will likely only make a noticeable difference in temperature in the short term just after the car is initially parked and while it is warming up.

If you park for any period at all, the car will eventually warm up anyways. The big difference in having the screen and not having the screen is how warm the dashboard will be after sitting in the sun for awhile. An opaque screen of any kind would keep the dashboard in the shade and therefore cooler.

But there are more sources of heat for the car than just the dasboard being heated up from the sun. The other windows are not shaded, the air in the car will warm up, the body of the car will warm up and radiate warmth into the interior of the car, and the shade itself will warm up over time - even if in the short term it reflects some of the sun - the material will warm up as the interior of the car gets hotter.

In any case, it is going to get hot - and you probably won't notice a difference using silver or gold or black.

Answer 2

Car Windshield Sunshade

Answer 3

Since silver is a brighter "color" than gold it will reflect the sun's rays more hence this is the side that should face the sun. The more radiation deflected the cooler your car.

Answer 4

You'd want to go with the more reflective side out, which means the whiter in color the better. Assuming both sides are equally shiny, the silver side would be better because it is closer to white and would reflect more light. Gold absorbs some wavelengths (which give it its color) and this translates into extra heat.

Answer 5

Gold reflects better than silver in the infrared and infrared radiation is absorbed by your car and produces heat, thus the gold side will keep your car cooler.

Answer 6

Silver. Silver is actually not a true color. It's the result of mixing tiny flakes of highly reflecting metal (usually aluminum) into the pigment. As such, it can be almost as refective as the shiny metal itself (refecting everything), but diffusely so instead of specular. Gold, however, means that it mostly just refects yellow and red while absorbing blue and green.

Answer 7

the silver side facing the sun

Answer 8

For glass, I have used a little rubbing alcohol on my house replacement windows. After they were installed, there were a few areas that had glue on the glass. I take a cleaning rag dipping corner of it in the alcohol, and lightly soak the glue and rub area. You can also again use a razor blade to lightly scrape it off after the rubbing alcohol has begun to break down the glue.

Answer 9

I would say silver side facing sun...

Answer 10

Hi
This silver auto sunshade with Silver reflective Coating surface for virtually 100% sun blocking.
so it is better to have the gold side facing to the outside to warm the car in the winter.

while, it is better to have the silver reflective side facing to the outside in the summer to cool the car.

when you use this silver nylon car sunshade like this link:

http://www.car-sunshade.com/car-front-silver-sunshade_p5.html