[Closed] Thermofoil to keep car cooler

Putting my foil screens in the front windows of the van definitely helps to keep it cooler in there.

Wind deflectors and windows down an inch works here.

It would do a better job on the outside in this use case.

Wind deflectors and windows down an inch works here.

Often get snails on my car so don't want to leave windows open for long.

snails on the car in this weather?
a little garlic butter, and voila!

It would do a better job on the outside in this use case.

Why is that? Is it because on the inside there will be a gap between the glass and foil?

Inside works and makes a huge difference. I seem to be about the only person in London they still puts a shade in my windscreen. Outside world work better, the glass acts to reflect some heat back, but inside is much more practical and does a good job.

It would do a better job on the outside in this use case.

Only to a limited extent, it would be reflecting not aborbing.

Wind deflectors and windows down an inch works here.

Left the sunroof open today, I think it just let more heat in!

Only to a limited extent, it would be reflecting not aborbing.

It would not be absorbing much the thermal capacity of effectively a thick bit of tin foil is limited in either case.

How ever once the heats through the glass it's already heating your car by convection and reflection and to an extent radiation from the tinfoil....

On the outside it's not getting into the car and it's air cooled by a much bigger air mass than that of the air trapped in your car.

While in the drive the windscreen is in direct sunlight.

Park facing in the opposite direction?

Park facing in the opposite direction?

Car has a large rear window too.

Park the car upside down. The bottom has heat shields and stuff built in anyway.

They work to an extent, but if the cars parked in direct 30c sunlight for 4 hours it won't make a huge difference.