is putting Aluminium foil behind the wind shield actually generate more heat and make the car hotter inside or make the car inside cooler? assume you put foil behind all windows.
it does it is just too thin to hold the heat once the heat source has been removed
Aluminum foil will absorb heat, just like any other metal (and anything for that matter, but this isn't a discussion about conductors vs. insulators). Whether aluminum foil absorbs heat is the essential issue here. A car gets hot in the sun as a result of the sunlight shining on the car. When the sun shines on a car, the light passes through the windows (because windows are clear) and is absorbs by the interior of the car (e.g. the seat cushions). The absorbed energy is given off as heat, which is trapped in the car (heat doesn't pass through windows like sunlight does). By putting aluminum reflectors in your windshield, you are reflecting away the light and preventing it from reaching the interior of your car. For this reason, putting aluminum shielding in the windows of your car actually keeps your car cooler, and not hotter.
Does Aluminum Foil Absorb Heat
Aluminum foil absorbs heat because the foil, like anything else, will absorb energy from a heat source according to thermodynamic principles. What that translates into is this: heat goes from where it is to where it isn't, or heat goes from where it's hot to where it's not. There are three ways for that to happen. One is convection, one is radiation and the third is conduction. If foil is exposed to flame, the hot combustion gases directly heat the foil when they come in contact with it. If the foil is sitting on the top of the range when the oven is on, the oven heats the air around it and convection currents are set. These convection currents take heat away from the oven and transfer it to things which the hot air passes over. Anyone who has had a hair dryer pointed at them knows what this is like. The skin reacts to the hot air. We feel it. Convection.
