Say you store a vehicle outside all winter, if there was an usually cold week, say -20 degrees Fahrenheit for example, is it possible for the car to be colder than the -20 since it sat weeks prior to the -20 temps?
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Sure, there’s a few mechanisms that can reduce an object’s temperature.
A) Radiation. Some objects will radiate particles off of them, which results in the object becoming colder as the most energetic (highest temperature) particles will tend to be ejected first.
B) Insulation. If an object is perfectly insulated at a lower temperature, and the ambient temperature raises, there’s no reason for that object to be the same temperature as ambient. In practice this doesn’t occur, but in principle it works.
C) Failure to absorb heat, such as when in shade or reflective properties. If the general area is being heated by the sun, but the object in question is reflective or shaded, it will tend to be colder than ambient.
D) Evaporation or phase change. When an object changes phases, it uses an incredible amount of energy to do so, decreasing the temperature of surrounding masses. For instance, it takes a significant amount of energy to turn ice into water, as opposed to just heating up water. By exploiting phase changes you can keep an object fairly cool compared to ambient (such as seen in air conditioners)
A good example of when an object might be colder than ambient is outer space; the temperature can actually get quite high, but because it’s a vacuum and there’s no atmosphere to transfer temperature around, you will often see objects that are colder than ambient, as they radiate off a decent amount of energy. In other words, they’re insulated, radiating, and will often fail to absorb heat if they’re manmade, as they will be often painted white or with a reflective material.
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