What I am wondering is why do cars parked in the carport when it is cold outside not get frost on thier windows while cars parked in the open do? Even cars parked a few feet away still get frost while the cars under the carport stay clear.
2007-12-17 08:32:39 · 3 answers · asked by Max L 2 in Science & Mathematics ➔ Weather
It has to do with radiating heat. On a clear night, there is nothing to stop heat radiating from the ground out to space. You may notice that frost will form even though a thermometer on a wall shows a temperature of 33 or 34F. That is because the ground can get colder than the air above it, by radiating heat to space.
The carport roof, open to space will do the same thing. But because it has air under it, it can't get colder than the air. This means the car under the roof has a 'hot' body above it, radiating heat back, so it doesn't cool down as much as the ground.
You may think that describing the roof as hot is silly, but space is around -270C. So compared to space, the roof is quite warm and will stop the car from cooling as much as cars in the open.
2007-12-17 09:28:04 · answer #1 · answered by mis42n 4 · 0⤊ 0⤋
The only reason I can see is that the air under the carport is warmer and hence does not reach the frost point. There may for example be some infrared escaping from the house that is being absorbed by the carport structure or even the car itself. But it must be a temperature difference. Try getting several precise temperatures under the carport, inside the car, and outside the carport and away from the house. See what you find.
2007-12-17 17:06:01 · answer #2 · answered by 1ofSelby's 6 · 1⤊ 0⤋
Probaby in your area,the wind is calm or very light so that it does not blow away the trapped ,compartively warm air between the roof and the ground. Sometimes , wind,if it blows, might have been blocked by adjacent buildings in all sides.
2007-12-17 22:30:08 · answer #3 · answered by Arasan 7 · 0⤊ 0⤋