The reason your car heats up much hotter than your house is because of all those windows. Cars have a much higher percentage of glass than an average building, of which only a few look at the sun at a time. Cars are more like greenhouses, which are specifically designed to absorb and retain heat. Yes, the same greenhouse effect that traps heat in the atmosphere and keeps our planet at a comfortable temperature for us to live in is also responsible for baking your car on warm days.
Not only does your car's windshield allow you a wide, unobstructed view while you're on the road, but it also allows sunlight to be an unobstructed path inside your car's interior. Just like shortwave radiation from the sun passes through car windows. These windows only heat up a little, but darker colored objects that hit the sun's rays (such as the dashboard, steering wheel, and seats) heat up immensely due to their lower albedo. These heated objects, in turn, heat the surrounding air by convection and conduction.
Car interiors create a greenhouse effect. The sun shining inside, through 360 degrees of glass, is quickly absorbed by the dashboard, seats and anything else in the car. And the same glass that allowed heat to enter the car, does not allow it to get out of the car, creating a greenhouse effect. There are many areas in your vehicle's cooling system that could lead to a leak, so this is the most common cause of engine overheating.
When a leak occurs, coolant cannot flow to critical parts of the engine, causing heat to build up without being released by the radiator. The greenhouse effect is also the reason why a car or truck feels like an oven on a hot day. Heat from the sun enters a vehicle through windows and is trapped inside, increasing the temperature. On a day when it is unbearably hot and there are no clouds in the sky, finding relief from the heat with a little shade when parking will make your car much more comfortable to return to.
There are more expensive, but much nicer windshield sunshades that can help keep your parked car cool. For even greater cooling action, use the foil type, as they actually reflect the sun's heat through the glass and away from the car. Follow these simple tips and you can keep your parked car cooler and more comfortable to drive. If you let your car overheat several times, you can damage the gaskets, engine block, and other critical engine components.
Using one of these car cooling methods or, better yet, a combination of them will keep a parked car cooler. Your car goes through a lot every day and picks up dirt, debris, road sediment, and other similar foreign materials. Unfortunately, it's a reality that neglectful parents leave their children alone in a hot car, with sometimes fatal results. A Stanford University study found that on a sunny day with temperatures ranging from 22°C to 35°C (72°F to 96°F), the temperature averaged 40°F higher (8°C) inside cars that had tested outside.
Simply parking in your home garage is an obvious solution to keeping your car cool, but it's something that many homeowners can't do. But if they still don't cool to your satisfaction, there are other ways to remove heat from a parked car faster. If you don't mind getting strange looks from passers-by, a simple method is to ventilate your car door to expel heat. If that's not an option, parking under a few trees on the edge of a parking lot or in the shade of a building can keep your car cooler and will be worth walking more than is required.