It wasn’t too long ago that air conditioning was an expensive luxury on a car, costing more than 10 percent of the cost of a vehicle. Today, it’s practically standard on every vehicle in America. And since Americans like to sit in traffic all day, AC has become a godsend in the heat. But what happens if the HVAC system starts to have a mind of its own and begins to make snow?
The owner and boyfriend of the 2006 Chevrolet Equinox in the below video noticed there was smoke coming out of the HVAC vents. “Oh, crap, maybe there’s exhaust gasses,” they thought, but it didn’t smell and they were pretty sure it wasn’t Freon either. So when the AC was turned on, what happened next? If you were paying attention to your Physics teacher, you’d understand how and why snow was shooting from the HVAC vents.
According to this Jalopnik article, “The snow is the result of the evaporator coil that acts as the heat exchanger to condition the air becoming too cold so the humidity is freezing and flaking off. The reason that the evaporator coil is becoming too cold is due to the fact that the system is low on refrigerant, most likely due to a leak in te system. Air conditioning is based on pressure-temperature relationship. When the closed system of refrigerant is low, it actually works “really well” until it gets too low on gas and starts freezing up the evaporator and condenser coils. The buildup if ice acts as an excellent insulator and renders the system useless as the coils that are meant to remove and dissipate heat are covered in insulating ice which prevents heat transfer. Source—growing up working for my grandfather’s comercial refrigeration business an a studying engineering in undergrad.”